Methods Retrospective case record examination of 7003 patients born before 1987 with autism who were enrolled with the California Department of Developmental Services between 1992 and 2005 was carried out. Of principal interest were 631 patients with a sole diagnosis of mental retardation (MR) who subsequently acquired a diagnosis of autism. The outcome of interest was the probability of acquiring a diagnosis of autism as a result of changes in diagnostic practices was calculated. The probability of diagnostic change is then used to model the proportion of the autism caseload arising from changing diagnostic practices.

Results The odds of a patient acquiring an autism diagnosis were elevated in periods in which the practices for diagnosing autism changed. The odds of change in years in which diagnostic practices changed were 1.68 [95% confidence interval (CI) 1.11–2.54], 1.55 (95% CI 1.03–2.34), 1.58 (95% CI 1.05–2.39), 1.82 (95% CI 1.23–2.7) and 1.61 (95% CI 1.09–2.39). Using the probability of change between 1992 and 2005 to generalize to the population with autism, it is estimated that 26.4% (95% CI 16.25–36.48) of the increased autism caseload in California is uniquely associated with diagnostic change through a single pathway—individuals previously diagnosed with MR.

Conclusion Changes in practices for diagnosing autism have had a substantial effect on autism caseloads, accounting for one-quarter of the observed increase in prevalence in California between 1992 and 2005.

Methods A population-based study was conducted among the cohort of children born in WA between 1983 and 1999 and diagnosed with ASD between the age of 2 and 8 years up to December 31, 2004. The trend in ASD diagnosis over the study period was assessed by investigating birth cohort and period effects, and examining whether these were modified by age of diagnosis. ASD diagnosis corresponding with changes in diagnostic criteria, funding and service provision over time were also investigated. A subgroup analysis of children aged ≤5 years was also conducted to examine trends in the incidence and age of diagnosis of ASD and intellectual disability (ID) and to investigate the role of changes in diagnostic practices.

Results The overall prevalence of ASD among children born between 1983 and 1999 and diagnosed by age 8 was 30 per 10 000 births with the prevalence of autism comprising 21 per 10 000 births. The prevalence of ASD increased by 11.9% per annum, from 8 cases per 10 000 births in 1983 to 46 cases per 10 000 births in 1999. The annual incidence of ASD, based on newly diagnosed ASD cases in each year from 1985 to 2002, increased over the study period. The increase in incidence of ASD appeared to coincide with changes in diagnostic criteria and availability of funding and services in WA, particularly for children aged <5 years. The age-specific rates of autism and PDD-NOS increased over time and the median age of diagnosis for autism decreased from 4 to 3 years of age throughout the 1990s. For children aged ≤5 years the incidence of ASD diagnosis increased significantly from 1992, with an average annual increase of 22%. Similar findings were found for autism. In the corresponding years the incidence of diagnosis of severe ID fell by 10% per annum and mild–moderate ID increased by 3% per annum.

Conclusions The rise in incidence of all types of ASDs by year of diagnosis appears to be related to changes in diagnostic and service provision practices in WA. In children aged ≤5 years, diagnosis of severe ID decreased, but mild–moderate ID increased during the study period. A true increase in ASD cannot be ruled out.

Methods The entire population at-risk aged 16–54 in Nottingham over three time periods (1978–80, 1993–95 and 1997–99) were followed up. All participants presenting with an ICD-9/10 first episode psychosis were included. The remainder of the population at-risk formed the denominator. Standardized incidence rates were calculated at each time period with possible change over time assessed via Poisson regression. We studied six outcomes: substance-induced psychoses, schizophrenia, other non-affective psychoses, manic psychoses, depressive psychoses and all psychotic disorders combined.

Results Three hundred and forty-seven participants with a first episode psychosis during 1.2 million person-years of follow-up over three time periods were identified. The incidence of non-affective or affective psychoses had not changed over time following standardization for age, sex and ethnicity. We observed a linear increase in the incidence of substance-induced psychosis, per annum, over time (incidence rate ratios: 1.15; 95% CI 1.05–1.25). This could not be explained by longitudinal changes in the age, sex and ethnic structure of the population at-risk.

Conclusions Our findings suggest psychotic disorders are not in decline, though there has been a change in the syndromal presentation of non-affective disorders, away from schizophrenia towards other non-affective psychoses. The incidence of substance-induced psychosis has increased, consistent with increases in substance toxicity over time, rather than changes in the prevalence or vulnerability to substance misuse. Increased clinical and popular awareness of substance misuse could also not be excluded.

Methods We examined whether job demands or job control contributed to the socioeconomic gradient in cerebrovascular disease among 48 361 women aged 18–65 years. Job demands, job control and behavioural risk factors were self-reported in 2000–2002; socioeconomic position (as indexed by occupational class) and all of the health measures were obtained from registers. The outcome was recorded hospitalization or death from cerebrovascular disease.

Results During a mean follow-up of 3.4 years, 124 women had a new cerebrovascular disease event. The risk was 2.3 (95% CI 1.3–3.9) times higher among women in low vs high socioeconomic positions. Adjustment for conventional risk factors, such as prevalent hypertension, coronary heart disease, diabetes, smoking, heavy alcohol consumption, physical inactivity and obesity, attenuated this excess risk by 23%. In contrast, adjustment for job demands and job control actually amplified the gradient by 36% suggesting a suppression effect.

Conclusions In this contemporary cohort of employed women, job demands—alone and in combination with job control—suppressed rather than explained socioeconomic differences in cerebrovascular disease.

Methods Cohort study—baseline data from the Norwegian total county population-based HUNT 2 study linked to mortality data (1995/97 to 2003). In this analysis, 18 247 men and 18 278 women aged 24–80 without severe chronic disease at baseline were eligible.

Results No socio-economic inequalities in mortality among women were found. In men, educational- and income-related inequalities in mortality were found with a relative risk for the lowest educational group of 1.67 (1.29–2.15) and the lowest income quartile of 2.03 (1.57–2.70). Together, the four explanatory factors reduced the relative risk of mortality of the lowest educational group to 1.18 (0.90–1.55) and the relative risk of mortality in the lowest income quartile was attenuated to 1.17 (0.83–1.63). Known biomedical factors contributed least to both educational and income inequalities in mortality.

Conclusions Material factors were the most important in explaining income inequalities in mortality amongst men, whereas psychosocial and behavioural factors were the most important in explaining educational inequalities. This suggests that improving the material, psychosocial and behavioural circumstances of men might bring more substantial reductions in relative socio-economic inequalities in mortality.

Methods A case–control study was conducted in Recife, Brazil, to investigate individual and area social determinants of tuberculosis, to explore the relationship between determinants at the two levels and to calculate their relative contribution to the burden of tuberculosis. It included 1452 cases of tuberculosis diagnosed by the tuberculosis services and 5808 controls selected at random from questionnaires completed for the demographic census. Exhaustive information on social factors was collected from cases, using the questionnaire used in the census. Socio-economic information for areas was downloaded from the census. Multilevel logistic regression investigated individual and area effects.

Results There was a marked and independent influence of social variables on the risk of tuberculosis, both at individual and area levels. At individual level, being aged ≥20, being male, being illiterate, not working in the previous 7 days and possessing few goods, all increased the risk of tuberculosis. At area level, living in an area with many illiterate people and where few households own a computer also increased this risk; individual and area levels did not appear to interact. Twice as many cases were attributable to social variables at individual level than at area level.

Conclusions Although individual characteristics are the main contributor to the risk of tuberculosis, contextual characteristics make a substantial independent contribution.

Methods A search of all published literature on the PubMed and ISI Web of Knowledge literature search engines was conducted using broad search terms. The authors reviewed abstracts and selected articles that met the inclusion criteria. A total of 26 published studies were included in the review.

Results Overall, SES was not consistently related to cortisol. Although several studies found an association between lower SES and higher levels of cortisol, many found no association, with some finding the opposite relationship. Lower SES was more consistently related to a blunted pattern of diurnal cortisol secretion, but whether this corresponded to higher or lower overall cortisol exposure varied by study. Approaches to collecting and analysing cortisol varied widely, likely contributing to inconsistent results. Lower SES was more consistently related to higher levels of AL, but primarily via the cardiovascular and metabolic components of AL rather than the neuroendocrine markers.

Conclusions Current empirical evidence linking SES to cortisol and AL is weak. Future work should standardize approaches to measuring SES, chronic stress and cortisol to better understand these relationships.

Methods We used twin data from the National Survey of Midlife Development in the United States, 1995–1996. The study population included 302 male [55.6% monozygotic (MZ) and 44.4% dizygotic (DZ)] and 387 female twin pairs (47.3% MZ and 52.7% DZ). A range of health outcomes [perceived global, physical and mental health, body mass index (BMI), waist circumference, waist–hip ratio, number of depressive symptoms] and health behaviours (smoking and physical activity) were examined among twin pairs who were discordant on years of schooling.

Results Among MZ twins, more years of education was associated with better perceived global health. For all other health outcomes/behaviours, the point estimates of the effect of education in the fixed-effect analyses suggested a weak protective association. Among DZ male twins, each additional year of schooling lowered the prevalence of smoking by 32% [odds ratio (OR): 0.68, 95% confidence interval (CI): 0.48–0.97] in the fixed-effect analysis.

Conclusion The widely reported associations between schooling and health outcomes/behaviours may not reflect causal relationships in every instance. Although low statistical power may explain some of the null associations, our twin fixed-effect analyses suggest that at least some cases of the education/health relationship reflect confounding by unobserved third variables.

Methods A model based on consumption data and demand elasticity was constructed to predict the effects of four food taxation-subsidy regimens. Resulting changes in demand, expenditure, nutrition, cardiovascular disease (CVD) and cancer mortality were estimated.

Data Expenditure data were taken from the Expenditure and Food Survey; estimates of price elasticities of demand for food were taken from a report based on the National Food Survey 1988–2000. Estimates of effect on CVD and cancer mortality of changing fat, salt, fruit and vegetable intake were taken from previous meta-analyses.

Results (i) Taxing principal sources of dietary saturated fat is unlikely to reduce cardiovascular disease (CVD) or cancer mortality. (ii) Taxing ‘less healthy’ foods (defined by the WXYfm nutrient profiling model) could increase CVD and cancer deaths by 35–1300 yearly. (iii) Taxing ‘less healthy’ foods and subsidising fruits and vegetables by 17.5% could avert up to 2900 CVD and cancer deaths yearly. (iv) Taxing ‘less healthy’ foods and using all tax revenue to subsidize fruits and vegetables could avert up to 6400 CVD and cancer deaths yearly. Few obesity-related CVD deaths are averted by any of the regimens. All four regimens would be economically regressive and positive health effects will not necessarily be greater in lower-income groups where the need for dietary improvement is higher.

Conclusions A targeted food tax combined with the appropriate subsidy on fruits and vegetables could reduce deaths from CVD and cancer.

Methods A national cohort of 447 929 children born during 1973–77 was followed prospectively in the National Patient Discharge Register from the end of their ninth and last year of compulsory school until 2001. Multivariate Cox analyses of proportional hazards were used to test hypotheses regarding grades in ninth grade as predictors of hospital admission due to self-inflicted injury.

Results The risk of hospital admission because of self-inflicted injury increased steeply in a step-wise manner with decreasing grade point average. Hazard ratios were 6.2 (95% confidence interval 5.5–7.0) in those with the lowest level of grade point average compared with the highest. The risks were similar for women and men. Adjustment for potential socio-economic confounders in a multivariate proportional hazards regression analysis attenuated this strong gradient only marginally.

Conclusion School performance is a strong factor for predicting future mental ill-health as expressed by self-inflicted injury.

Methods The data are from Demographic and Health Surveys conducted in Cambodia, Dominican Republic, Haiti, Jordan, Moldova, Namibia and Nepal between 2005 and 2007. The respondents were women (15–49 years) and their children in seven countries (n = 28 439), and men (15–59 years) from four countries. The outcome is a physical measurement of child height-for-age in standard deviation units.

Results Multilevel regression analysis showed that the country of residence modified the association between maternal smoking and child height-for-age. Exposure to maternal smoking was associated negatively with child height-for-age in Cambodia, Namibia and Nepal, whereas it was not in other countries. Multilevel regression analysis revealed that biofuel smoke exposure was associated with a decrease in child height-for-age [b = –0.13, 95% confidence interval (CI) = –0.19 to –0.07, P < 0.001]. No interaction was found between country of residence and biofuel smoke exposure. Multinomial logistic regression results showed that biofuel smoke exposure was associated with both stunting [odds ratio (OR) = 1.25, 95% CI = 1.08–1.44, P = 0.002) and severe stunting (OR = 1.27, 95% CI = 1.02–1.59, P = 0.04), after controlling for covariates.

Conclusion The findings suggest that exposure to maternal smoking and biofuel smoke may contribute to growth deficiencies in young children. Programmes are needed to ensure smoke-free home environments for children.

Methods A population-based cohort of newborns was followed from birth through 6 months. Household characteristics were assessed during an enrolment interview including the primary type of cooking fuel and smoking behaviour of household residents. Follow-up visits for morbidity were carried out every 2 weeks after delivery. Infants were discharged at 6 months when anthropometric measurements were collected.

Results 11 728 live-born infants were enrolled and followed, of whom 92.3% resided in households that used wood and/or dung as a primary source of fuel. Exposure to biomass fuel was associated with an adjusted 49% increased risk of LBW, a 34% increased incidence of respiratory illness and a 21% increased risk of 6-month infant mortality. Exposed infants also had 45 and 30% increased risks of underweight and stunting at 6 months. SHTS exposure was also associated with these adverse health outcomes except for attained growth.

Conclusions Open burning of biomass fuel in the home is associated with significant health risks to the newborn child and young infant. Community-based trials are needed to clarify causal connections and identify effective approaches to reduce this burden of illnesses.

Methods Using data from a GWA scan for type 2 diabetes (1924 cases, 2938 controls, 393 453 SNPs), we compared P-values with four alternative signal measures: likelihood ratio (LR), Bayes factor (BF; with a specified prior distribution for true effects), ‘frequentist factor’ (FF; reflecting the ratio between estimated—post-data— ‘power’ and P-value) and probability of pronounced effect size (PrPES).

Results The 19 common SNPs [minor allele frequency (MAF) among the controls >29%] yielding strong P-value signals (P < 5 x 10^–7) were also top ranked by the other approaches. There was a strong similarity between the P-values, LR and BF signals, in terms of ranking SNPs. In contrast, FF and PrPES signals down-weighted rare SNPs (control MAF <10%) with low P-values.

Conclusions For prioritization of signals that do not achieve compelling levels of evidence for association, the main driving force behind observed differences between the various association signals appears to be SNP MAF. The statistical power afforded by follow-up samples for establishing replication should be taken into account when tailoring the signal selection strategy.

Methods We used logistic regression models to examine the associations in men and women aged 60–79 years from the English Longitudinal Study of Ageing (ELSA, n = 3158) and InCHIANTI (n = 761) population studies. Outcomes included the Center for Epidemiologic Studies Depression (CES-D) scale, self-rated general health status and (in ELSA only) diagnoses of depression.

Results The PON1 Q192R polymorphism was not associated with self-reported poor health {meta-analysis: odds ratio (OR) = 1.01 [confidence interval (CI) 0.91–1.13], P = 0.80} or depressive symptoms in either study or in meta-analyses [CES-D: OR = 1.01 (CI 0.87–1.17), P = 0.90]. There was also no association with histories of diagnosed depression in ELSA [OR = 1.03 (CI 0.82–1.30), P = 0.80].

Conclusions We found no evidence of an association between the PON1 Q192R polymorphism and poor general or mental health in two independent population-based studies. Neither the claimed Q192R association with depression in the general population nor its theoretical implications were supported.

Methods This was a secondary analysis of data from a population-based prospective cohort study in 13 counties of East China (1993–96). All singleton live births delivered at 20–44 weeks to women with at least one haemoglobin measure during pregnancy were included (n = 160 700). Risk of preterm birth (<37 weeks) was examined by clinical subtypes, namely, preterm premature rupture of membranes (PROM), spontaneous preterm labour and medically indicated preterm birth. Haemoglobin changes across trimesters were assessed as proxy of haemo-dilution and haemo-concentration. Multivariable Cox proportional hazards regression models were fitted.

Results Preterm birth rates of preterm birth were 4.1% for anaemic and 5% for non-anaemic women (P < 0.05). Compared with haemoglobin of 11 g/dl (reference), values ≤5 g/dl in the first trimester were associated with increased risk for preterm PROM [hazard ratio (HR) 3.3, 95% confidence interval (CI) 1.4–7.7], whereas low haemoglobin in the third trimester was associated with reduced risk of spontaneous preterm labour. Haemodilution was associated with reduced risk for preterm birth.

Conclusions Anaemia in early pregnancy was found to be associated with increased risk for preterm PROM, whereas exposure in late pregnancy was associated with reduced risk for spontaneous preterm labour.

Aim To examine the nature of the association between birth weight and a range of behavioural symptoms, including anxiety/depression and social problems, in adolescence.

Methods Data from 4971 mothers and their children participating in the Mater University Study of Pregnancy (MUSP), a prospective, population-based birth cohort, are presented. This study commenced in Brisbane, Australia, in 1981. Mothers and their children were followed up at 3–5 days post-birth, and 6 months, 5 years and 14 years after the initial interview. Internalizing and externalizing behaviour problems, social problems and anxiety/depressive symptoms were assessed using Achenbach's Youth Self Report (YSR) of the Child Behaviour Check List (CBCL).

Results There was no evidence of a linear association between birth weight and behavioural symptoms, when birth weight z-scores were examined as a continuous variable. However, a non-linear association was identified when birth weight z-scores were categorized into quintiles. Children in the lowest and highest quintiles were at higher risk of increased anxiety/depressive and social problems symptoms. After adjustment for potential confounders, birth weight showed a non-linear association with the log odds of social problems {Quintile 1 odds ratio (OR) 1.59 [95% confidence interval (CI) 1.13, 2.23] Quintile 5 OR 1.57 (95% CI 1.12, 2.20)}.

Conclusions Our findings provide further support for an association between birth weight and some adolescent behaviour problems. This association is likely to be non-linear, affecting babies at both the lower and higher ends of the birth weight distribution.

Methods A total of 1288 Senegalese subjects were followed from infancy to young adulthood (mean age 17.9 years). Adult systolic blood pressure (SBP) was regressed on infant and adult anthropometric characteristics.

Results In unadjusted analyses, infant size was positively associated with adult SBP (1.1 ± 0.3; P = 0.001 for weight; 0.7 ± 0.3; P = 0.04 for length). With adjustment for current size, the regression coefficients for infant size were reversed (–0.2 ± 0.3; P = 0.51 for weight; –0.3 ± 0.3; P = 0.35 for length). SBP increased by 4.1 and 2.9 mmHg for 1 standard deviation (SD) increase in current weight or height, respectively. No interaction between infant size and current size was found in the overall models (P = 0.11 for weight, P = 0.95 for height), but this term interacted with sex for weight effect. A negative interaction was found in males (–0.9 ± 0.4; P = 0.02) but not in females (0.3 ± 0.4; P = 0.46). The association of current weight with SBP was stronger in lighter weight male infants.

Conclusions These findings support the hypothesis that subjects who were small in early life and experienced enhanced post-natal growth have higher levels of SBP, even in low-income settings.

Methods A sample of 1029 children was drawn from Birth to Twenty, a longitudinal cohort followed from pregnancy to young adulthood. This sample completed the Youth Self Report at age 12 years, a validated psychological measure of behavioural and emotional adjustment. Scores were compared between LBW (<2500 g) and normal birthweight children using multivariate analysis with adjustment for potential birth and life events confounding factors.

Results No associations were found between LBW and total [adjusted odds ratio (OR) 1.09, 95% confidence interval (CI) 0.69–1.74], internalizing (adjusted OR 0.81, 95% CI 0.52–1.28) or externalizing profiles (adjusted OR 0.81, 95% CI 0.49–1.36). The only difference detected was for the internalizing sub-profile of Somatic Complaints (adjusted OR 2.02, 95% CI 1.21–3.38), which on subgroup analysis was greatest among females.

Conclusions We found no convincing evidence of an association between LBW and emotional and behavioural outcomes in 12-year olds in this sample in urban South Africa. To our knowledge, this is the first published assessment of this association in a developing world context.

Methods Population-based cohort study of 35 846 men and women born between 1920 and 1959 with mortality follow-up from 1961 to 2005.

Results During follow-up, 630 people died from CHD and there was an inverse association of head circumference with deaths from CHD (P_trend = 0.010). The association was modified by maternal height (P_interaction = 0.01) and by adult body mass (P_interaction = 0.05). People in the lowest third of head circumference, who had a tall mother or a high body mass index in adulthood, were at the highest risk of death from CHD.

Conclusions Head circumference at birth was inversely associated with deaths from CHD, and the combination of small head and tall mother, or small head and high adult body mass, was associated with the highest risk. These findings suggest that combined effects of genetic factors (growth potential and intrauterine growth) and non-genetic factors acting throughout the life course (intrauterine growth restriction and later weight gain) could mediate the effects of birth size on adult heart disease.

Methods The theory is based on nocturnal light-induced disruption of circadian rhythms, notably reduction of melatonin synthesis. It has formed the basis for a series of predictions including that non-day shift work would increase risk, blind women would be at lower risk, long sleep duration would lower risk and community nighttime light level would co-distribute with breast cancer incidence on the population level.

Results Accumulation of epidemiological evidence has accelerated in recent years, reflected in an International Agency for Research on Cancer (IARC) classification of shift work as a probable human carcinogen (2A). There is also a strong rodent model in support of the light-at-night (LAN) idea.

Conclusion If a consensus eventually emerges that LAN does increase risk, then the mechanisms for the effect are important to elucidate for intervention and mitigation. The basic understanding of phototransduction for the circadian system, and of the molecular genetics of circadian rhythm generation are both advancing rapidly, and will provide for the development of lighting technologies at home and at work that minimize circadian disruption, while maintaining visual efficiency and aesthetics. In the interim, there are strategies now available to reduce the potential for circadian disruption, which include extending the daily dark period, appreciate nocturnal awakening in the dark, using dim red light for nighttime necessities, and unless recommended by a physician, not taking melatonin tablets.

Methods To avoid these biases we used a Mendelian randomization approach incorporating an analysis of variants in the FTO gene that are strongly associated with BMI levels among 7000 subjects from a study of lung, kidney and upper-aerodigestive cancer.

Results The FTO A allele which is linked with increased BMI was associated with a decreased risk of lung cancer (allelic odds ratio (OR) = 0.92, 95% confidence interval (CI) 0.84–1.00). It was also associated with a weak increased risk of kidney cancer, which was more apparent before the age of 50 (OR = 1.44, CI 1.09–1.90).

Conclusion Our results highlight the potential for genetic variation to act as an unconfounded marker of environmentally modifiable factors, and offer the potential to obtain estimates of the causal effect of obesity. However, far larger sample sizes than studied here will be required to undertake this with precision.

Methods Data were obtained from a population-based case–control study conducted between 2003 and 2007 with 300 histologically proven OSCC cases and 571 matched neighbourhood controls. We used conditional logistic regression to compare cases and controls for individual SES indicators, for a composite wealth score constructed using multiple correspondence analysis, and for factors obtained from factors analysis.

Results We found that various dimensions of SES, such as education, wealth and being married were all inversely related to OSCC. The strongest inverse association was found with education. Compared with no education, the adjusted odds ratios (95% confidence intervals) for primary education and high school or beyond were 0.52 (0.27–0.98) and 0.20 (0.06–0.65), respectively.

Conclusions The strong association of SES with OSCC after adjustment for known risk factors implies the presence of yet unidentified risk factors that are correlated with our SES measures; identification of these factors could be the target of future studies. Our results also emphasize the importance of using multiple SES measures in epidemiological studies.

Methods Between October 2002 and October 2005, 242 (178 male, 64 female) patients with histologically confirmed lung cancer and two controls for each patient (242 hospital controls and 242 visiting healthy controls) matched for age, sex and place of residence were interviewed using a structured questionnaire on potential risk factors for lung cancer, including environmental and occupational exposures. Associations between risk factors and lung cancer were assessed using conditional logistic regression.

Results Smokers were 66.5% of all cases (85.4% of men and 14.1% of women) and smoking was the strongest correlate of lung cancer in multivariate analysis [odds ratio (OR) 5.4, 95% confidence interval (CI) 3.2–8.9]. Occupational exposures to inorganic dusts (OR 4.2, 95% CI 2.8–6.7), chemical compounds (OR = 3.4, 95% CI 2.1–5.6) and heavy metals (OR 3.0, 95% CI 1.3–7.0) were also independent risk factors for lung cancer.

Conclusions In our study, smoking was the principal risk factor for lung cancer. However, preventable exposures in the environment, including occupational settings, should not be ignored.

Methods We analysed data from a prospective study of hormonal contraception and HIV acquisition among Zimbabwean and Ugandan women (1999–2004), in which HIV testing and counselling were performed approximately every 3 months. We used zero-inflated negative binomial (ZINB) models to examine the number and proportion of unprotected sex acts, comparing behaviour reported 2–6 months before HIV testing with behaviour reported both 2–6 months (short-term analysis) and 12–16 months (long-term analysis) after HIV testing.

Results Short- and long-term analyses were similar, so we present only long-term findings from 151 HIV-infected and 650 uninfected participants. The proportion of HIV-infected women reporting any unprotected acts in a typical month declined from 74% (pre-infection behaviour) to 56% (12–16 months after HIV diagnosis). In multivariable models, HIV-infected women were twice as likely to report that all sex acts were protected by condoms after diagnosis compared with beforehand [adjusted odds ratio (aOR): 1.99, 95% confidence interval (CI): 1.12–3.53]; uninfected women were somewhat less likely to report that all acts were protected (aOR: 0.82, 95% CI: 0.64–1.04). HIV-infected women also reduced their number of unprotected acts by 38% (95% CI: –16 to –55%). However, their proportion of unprotected acts changed little (7% reduction, 95% CI: –18 to + 6%). Uninfected women reported little change in number or proportion of unprotected acts over the same time period.

Conclusions HIV-infected women reduced the number, but not the proportion, of unprotected acts. HIV-negative women did not increase condom use after testing and counselling, but neither did they decrease condom use, suggesting that testing negative was not interpreted as endorsement of risky behaviour.

Methods All 12 221 participants who consented to an HIV test in a population under continuous demographical surveillance were linked to their homesteads and geo-located in a geographical information system (accuracy of <2 m). We then used a two-dimensional Gaussian kernel of radius 3 km to produce robust estimates of HIV prevalence that vary across continuous geographical space. We also applied a Kulldorff spatial scan statistic (Bernoulli model) to formally identify clusters of infections (P < 0.05).

Results The results reveal considerable geographical variation in local HIV prevalence (range = 6–36%) within this relatively homogenous population and provide clear empirical evidence for the localized clustering of HIV infections. Three high-risk, overlapping spatial clusters [Relative Risk (RR) = 1.34–1.62] were identified by the Kulldorff statistic along the National Road (P ≤ 0.01), whereas three low risk clusters (RR = 0.2–0.38) were identified elsewhere in the study area (P ≤ 0.017).

Conclusions The findings show the existence of several localized HIV epidemics of varying intensity that are partly contained within geographically defined communities. Despite the overall high prevalence of HIV in many rural South African settings, the results support the need for interventions that target socio-geographic spaces (communities) at greatest risk to supplement measures aimed at the general population.

Methods A total of 1839 males and 870 females treated in 2000–03 by state TB clinics were interviewed at home in 2004–05 about their education, smoking and drinking habits before disease onset. As controls, 2134 men and 2119 women without TB were randomly chosen from case villages and interviewed. Incidence rate ratios (RRs) are from logistic regression, adjusted for age and education.

Results No women smoked or drank. The main analyses are of men aged 35–64 years, 949 cases treated for new pulmonary TB and 1963 controls. In the study, 81.5% of the cases and 55.2% of the controls had ever smoked, yielding a standardized ever- vs never-smoker TB incidence RR of 2.7 [95% confidence interval (CI) 2.2–3.3, P < 0.00001). Among control ever-smokers 96% still smoked, 71% used only bidis (mean 17 per day) and 28% used only cigarettes (mean 7 per day). After additional adjustment for alcohol, this RR was 2.2 (95% CI 1.7–2.7, P < 0.00001), but even among those who had never drunk alcohol the standardized ever- vs never-smoker RR was 2.6 (95% CI 2.0–3.6, P < 0.00001). The corresponding RRs for ever- vs never-drinking were somewhat less extreme: 2.2 (95% CI 1.8–2.6, P < 0.00001) without adjustment for smoking, 1.5 (95% CI 1.2–1.9, P = 0.00004) with adjustment for smoking and 2.1 (95% CI 1.4–3.0, 2P = 0.0001) among those who had never smoked. Among control ever-drinkers, 96% still drank and 99% used only spirits (mean 0.3 l/week).

Conclusions This study of reliably confirmed disease (by the criteria of state TB clinics) demonstrates an increased incidence of pulmonary TB among those who smoke and among those who drink. The effects of smoking after adjustment for drinking were more definite than those of drinking after adjustment for smoking.

Methods A community-based cross-sectional tuberculosis (TB) disease prevalence survey was undertaken among adults aged ≥15 years in the tribal population of Madhya Pradesh. A multistage stratified cluster sampling was adopted. A representative random sample of villages predominated by tribal populations was selected from 11 districts. All eligible individuals were questioned for chest symptoms relating to TB. Sputum samples were collected from all eligible individuals, transported to the laboratory, and examined by Ziehl–Neelsen (ZN) smear microscopy and solid media culture methods.

Results Of the 23 411 individuals eligible for screening, 22 270 (95.1%) were screened for symptoms. The overall proportion of symptomatic individuals was 7.9%. Overall prevalence (culture and/or smear positive) of PTB was 387 [95% confidence interval (CI): 273–502] per 100 000 population. The prevalence increased with age and was also significantly higher among males (554/100 000; 95% CI: 415–693) as compared with females (233/100 000; 95% CI: 101–364) (P < 0.001).

Conclusion The findings suggest that the TB situation amongst the tribal population is not that different from the situation among the non-tribal population in the country. However, TB remains a major public health problem amongst the tribal population and there is a need to maintain and further strengthen TB control measures on a sustained and long-term basis.

Methods The National Trauma Survey (NTS) of Rwandans aged 8–19 measured traumatic exposures using an inventory of possible war time experiences and post-traumatic stress reactions with a checklist of symptoms of Post-traumatic stress disorder (PTSD). Individuals meeting assessed PTSD diagnostic criteria are classified as cases of ‘probable PTSD’. The NTS interviewed youth residing in the community and others institutionalized in unaccompanied children's centres; the former (n = 1547) are the subject of the present report. Instrument change midway into the study divides respondents into two samples.

Results Among respondents, over 90% witnessed killings and had their lives threatened; 35% lost immediate family members; 30% witnessed rape or sexual mutilation; 15% hid under corpses. In Sample 1, 95% of respondents reported one or more re-experiencing symptom, 95% reported three or more avoidance/blunting symptoms and 63% reported two or more arousal symptoms; in Sample 2, these figures were 96%, 95% and 56%, respectively. The overall rate of ‘probable PTSD’ was 62% and 54% in Samples 1 and 2, respectively, and exhibited a dose–response relationship with exposure. Among the most heavily exposed individuals the rate was 100%. Rates of ‘probable PTSD’ were higher among females than among males. Results for age were inconsistent.

Conclusion In industrialized societies, most survivors of traumatizing violence experience symptoms only transiently. In the Rwanda survey, symptom levels and rates of ‘probable PTSD’ were exceptionally elevated, suggesting that at the limits of catastrophic man-made violence, psychological resilience among youth is all but extinguished.

Methods We completed a cross-sectional study of a community sample of 3700 men aged ≥70 years, and used the 15-item Geriatric Depression Scale (GDS-15) to assess depressive symptoms. A GDS-15 score 7 or more indicates the presence of clinically significant depressive symptoms. Physical morbidity was assessed with the physical component summary score (PCS) of the SF-36 Health Survey. We collected fasting blood samples to measure high sensitivity CRP and to extract DNA for the genotyping of SNPs rs1130864 and rs1205 of the CRP gene.

Results One hundred and eighty-two men were depressed (4.9%). The odds of depression increased by 2% (95% CI = 1–4%) for every unit (mg/l) increase of CRP and nearly doubled for men with CRP ≥ 3 mg/l vs <1 mg/l [odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.27–2.98]. However, the association between high CRP (≥3 mg/l) and depression was no longer significant after the analyses were adjusted for smoking, age, body mass index (BMI) and PCS. Men with the CT and TT genotypes of rs1130864 had 1.36 (95% CI = 1.13–1.63) and 2.31 (95% CI = 1.65–3.24) greater odds of CRP ≥3 mg/l than CC carriers, but there was no association between this polymorphism and the presence of prevalent depression. The G > A polymorphism of SNP rs1205 was associated with 24% (95% CI = 16–32%) lower concentration of CRP compared with other genotypes. Men with the rs1205 AA genotype had 1.66 (95% CI = 1.07–2.57) and 1.67 (95% CI = 1.08–2.58) greater odds of having clinically significant depression than participants with the GA and GG genotypes, respectively.

Conclusion Our study shows that clinically significant depressive symptoms in later life are unlikely to be caused by an increase in the serum concentration of CRP. Instead, we found that the risk of depression was greater amongst people who carry the rs1205 G > A genetic polymorphism of the CRP gene, which was associated with ~20% lower serum concentration of CRP compared with other genotypes. This suggests that CRP may be a compensatory response to external insults that predispose to depression, and that an increase in the concentration of CRP might be adaptive.

Methods Thirty-nine studies from the Asia Pacific Cohort Studies Collaboration database were included. We used Cox proportional hazard regression models to estimate the associations between height and pre-specified outcomes.

Results A total of 510 800 participants with 21 623 deaths were included. Amongst men, inverse linear associations were observed between height and coronary heart disease (CHD), stroke, CVD, injury and total mortality. The hazard ratios [95% confidence intervals, (CI)] for a 1-SD (= 6 cm) increment in height ranged from 0.85 (0.80–0.91) for injury to 0.97 (0.95–0.98) for total mortality. Similar trends were found between height and CHD, haemorrhagic stroke and CVD in women. A positive linear association was observed between height and cancer mortality. For each standard deviation greater height, the risk of cancer was increased by 5% (2–8%) and 9% (5–14%) in men and women, respectively. No regional difference was observed between Asian and Australasian cohorts. Adjusting for markers of education did not alter the results.

Conclusions The opposing relationships of height with CVD and cancer suggest that care is required in setting national policies on childhood nutrition lest they have unintended consequences on the incidence of major non-communicable diseases.

Methods Data from individual studies and review articles known to the authors were examined. A Medline bibliographic database search was also performed. Reference lists were reviewed to identify additional relevant data sources. Key references were examined by both authors.

Results We propose, and evaluate, the evidence for a ‘mitochondrial efficiency hypothesis’ i.e. that ancestral changes in mitochondrial coupling efficiency enhanced the successful adaptation of South Asians to environmental stressors by maximizing the conversion of energy to adenosine triphosphate (ATP) rather than heat. This adaptation may be disadvantageous when South Asians are physically inactive and consume high-caloric diets. There is evidence that common mitochondrial mutations vary geographically. Mutations, including those affecting the function of mitochondrial uncoupling proteins (UCPs), may influence the balance of energy and heat production. These may influence basal metabolic rate (BMR), energy efficiency, the tendency to gain weight and hence metabolic disease. UCP gene polymorphisms are related to differences in BMR between African-Americans and Europeans. Similar data for South Asians are lacking but the few studies comparing BMR indicate that South Asians have a lower BMR, which is explained by a lower lean body mass, and higher fat mass. Once adjusted for body composition, BMR is similar. A high fat mass, per se, is a strategy for reducing energy use while conserving body size. Indians in the USA had higher oxidative phosphorylation capacity than Northern European Americans.

Conclusion The evidence justifies full exploration of this mitochondrial effeciency hypothesis in South Asians, which may also be relevant to other warm-climate adapted populations.

Methods Cross-sectional study of urban primary school children (2006–07). Actigraph-GT1M activity monitors were worn by 2071 children during waking hours on at least 1 full day. Ethnic differences in mean daily activity [counts, counts per minute of registered time (CPM) and steps] were adjusted for age, gender, day of week and month. Multilevel modelling allowed for repeated days within individual and clustering within school.

Results In white Europeans, mean daily counts, CPM and mean daily steps were 394 785, 498 and 10 220, respectively. South Asian and black Caribbean children recorded more registered time per day than white Europeans (34 and 36 min, respectively). Compared with white Europeans, South Asians recorded 18 789 fewer counts [95% confidence interval (CI) 6390–31 187], 41 fewer CPM 95% CI 26–57) and 905 fewer steps (95% CI 624–1187). Black African–Caribbeans recorded 25 359 more counts (95% CI 14 273–36 445), and similar CPM, but fewer steps than white Europeans. Girls recorded less activity than boys in all ethnic groups, with 74 782 fewer counts (95% CI 66 665–82 899), 84 fewer CPM (95% CI 74–95) and 1484 fewer steps (95% CI 1301–1668).

Conclusion British South Asian children have lower objectively measured physical activity levels than European whites and black African–Caribbeans.

Methods Maternal anthropometry, dietary intakes (24-h recall and food-frequency questionnaire) and activity pattern (questionnaire) at 18 ± 2 and 28 ± 2 weeks gestation, and neonatal anthropometry, were measured in a prospective study of 797 rural Indian women.

Results Maternal energy and protein intakes were inadequate (70% of recommended dietary allowance). Both intake and activity showed seasonal variation (P = 0.001), with peak values in winter i.e. during harvest, at 18 weeks (median energy 1863 kcal/day, protein 47.5 g/day) and 28 weeks (median energy 1687 kcal/day, protein 43.7 g/day), coinciding with the maximum maternal activity (median score 86.1 at 18 weeks and 79.5 at 28 weeks). Mean birth weight and length (adjusted for pre-pregnant weight, parity, gestation and sex) of babies was highest in summer (peak at February 2733 g, 48.6 cm, respectively) and lowest in winter (nadir at January 2591 g, 47.1 cm, respectively). Regression analysis showed that maternal intake at 18th week had a positive association (P = 0.05), maternal activity at 28th week had a negative association (P = 0.002) and exposure (in weeks) to winter during gestation had a positive association (P = 0.04) with birth size. Furthermore, higher maternal intakes, coupled with lower maternal activity in late gestation were associated with higher birth weight, especially during winter.

Conclusions If causal, these observations indicate that complete exposure (16 weeks) to the winter season (harvest-time) in late gestation could increase birth weight by 90 g in poor farming communities in rural India, and the benefit would increase further by lowering maternal activity. Our results underscore the importance of considering seasonality in planning targeted intervention strategies in such settings.

Methods National legislation case analysis.

Results In accordance with European regulation, French observational studies from data obtained without any additional therapy or monitoring procedure, do not need the approval of an IRB/IEC. Nevertheless, these studies are neither exempt from scientific opinion nor from ethical and legal authorization.

Conclusion We wish to demonstrate through the study of this example that different bodies of law can provide equivalent levels of protection that respect the same ethical principles. Our purpose in writing this article was to encourage public bodies, scientific journals and researchers to gain a better understanding of the various sets of specific national regulations and to speak a common language.

Methods We address the logic of the implicit argument that the transient infections were an artifact and we demonstrate a simple likelihood calculation to assess the plausibility of competing explanations. We calculate the likelihood of observing our data based on a range of clearance and measurement error rates and then how this updates a set of prior beliefs.

Results The likelihood calculations and resulting posterior probabilities show strong support for the hypothesis of spontaneous clearance, after allowing for measurement error, even starting with a very high prior probability of no spontaneous clearance. The scenario Perry and Parsonnet present is incompatible with our data, and thus not a plausible explanation for our observations. Attributing most observed transient infections to measurement error requires assuming a high false positive rate and a very low infection rate and/or a high false negative rate, alternatives that are not supported by evidence.

Conclusions Acknowledgment of plausible levels of measurement error does not change the strong support our data provides for the hypothesis of frequent transient infection. Debate about competing explanations for observations should be accompanied by quantitative analysis that shows which is more plausible. We demonstrate one method for doing such analysis.

Methods A randomized experiment was embedded in a telephone survey that drew probability samples of the populations of the USA (N = 1543) and Baltimore city (N = 744). Respondents were randomly assigned to have questions asked either by a T-ACASI computer or by a human telephone interviewer.

Results Compared with interviewer-administered telephone surveys, T-ACASI obtained more frequent reporting of a range of mainly heterosexual behaviours that were presumed to be sensitive, including recency of anal sex [adjusted odds ratio (A-OR) = 2.00, P < 0.001), sex during menstrual period (A-OR = 1.49, P < 0.001), giving oral sex (A-OR = 1.40, P = 0.001) and receiving oral sex (A-OR = 1.36, P = 0.002), and sexual difficulties for the respondent (A-OR = 1.45, P = 0.034) and their main sex partner (A-OR = 1.48, P = 0.0). T-ACASI also obtained less frequent reporting that respondent had a ‘main sex partner’ (A-OR = 0.56, P = 0.011) and discussed contraception prior to first sex with that sex partner (A-OR = 0.82, P = 0.094). For both males and females, T-ACASI obtained more frequent reports of first vaginal sex occurring at early ages (before ages 12 through 15). ‘For males only’, T-ACASI also elicited more frequent reports that first vaginal sex had ‘not’ occurred at later ages (i.e. by ages 20 through 24).

Conclusion T-ACASI increases the likelihood that survey respondents will report sensitive heterosexual behaviours.

Methods We studied all 84 338 pairs of drivers and front-seat passengers aged >=18 years in passenger cars involved in traffic crashes with victims recorded in the Spanish traffic crash registry between 2000 and 2004. Relative risks (RR) for the association of age, male sex and non-seat belt use with risk of death were calculated with Poisson conditional and unconditional multiple regression models.

Results For drivers, the risk of death associated with severity of the crash was slightly higher in men (RR = 1.18), and decreased with age (RR = 0.993 per year). However, resilience-dependent risk of death increased with age (RR = 1.028 per year), and especially among unbelted occupants (RR = 4.02).

Conclusions We conclude that in drivers involved in traffic crashes the association of age, sex and seat belt use with risk of death depends on the component of risk considered: severity of the crash or the occupant's resilience to energy.

Methods We estimated the food energy required to maintain basal metabolic rate in two hypothetical adult populations using the Schofield equations for males and females. Additional greenhouse gas emissions due to higher fuel energy use for transporting a heavier population were estimated.

Results Compared with a normal population distribution of BMI, a population with 40% obese requires 19% more food energy for its total energy expenditure. Greenhouse gas emissions from food production and car travel due to increases in adiposity in a population of 1 billion are estimated to be between 0.4 Giga tonnes (GT) and 1.0 GT of carbon dioxide equivalents per year.

Conclusions The maintenance of a healthy BMI has important environmental benefits in terms of lower greenhouse gas emissions.

Methods Using a case–control design, we analysed data from 97 215 women of the Etude Epidémiologique auprès de femmes de l’Education Nationale study, a cohort of 98 995 French women insured by a national health scheme mostly covering teachers, and aged 40–65 years at inclusion in 1990. Risk estimates were computed using unconditional logistic regression models.

Results After adjustment for potential confounding factors, there was a positive dose–effect relationship between risk of endometriosis (reported as surgically ascertained, n = 4241) and skin sensitivity to sun exposure [moderate: odds ratio (OR) 1.09, 95% confidence interval (CI) 0.99–1.19; high: OR 1.22; 95% CI 1.10–1.36; compared with none; P_trend < 0.0001], number of naevi (few: OR 1.19, 95% CI 1.05–1.35; many: OR 1.37, 95% CI 1.21–1.55; very many: OR 1.59, 95% CI 1.37–1.83; compared with none; P_trend < 0.0001) and number of freckles (few: OR 1.08, 95% CI 1.00–1.17; very many/many: OR 1.11, 95% CI 1.03–1.20; compared with none; P_trend = 0.005).

Conclusion This study is, to our knowledge, the first to report a positive dose–effect relationship between the risk of endometriosis and skin sensitivity to sun exposure, and number of naevi and freckles. These data suggest that endometriosis and melanoma may share some genetic features.

Methods Within a population-based birth cohort, both mothers and fathers reported on their smoking habits at several time-points during pregnancy. Behavioural problems were measured with the Child Behavior Checklist in 4680 children at the age of 18 months.

Results With adjustment for age and gender only, children of mothers who continued smoking during pregnancy had higher risk of Total Problems [odds ratio (OR) 1.59, 95% confidence interval (CI): 1.21–2.08] and Externalizing problems (OR 1.45, 95% CI: 1.15–1.84), compared with children of mothers who never smoked. Smoking by father when mother did not smoke, was also related to a higher risk of behavioural problems. The statistical association of parental smoking with behavioural problems was strongly confounded by parental characteristics, chiefly socioeconomic status and parental psychopathology; adjustment for these factors accounted entirely for the effect of both maternal and paternal smoking on child behavioural problems.

Conclusions Maternal smoking during pregnancy, as well as paternal smoking, occurs in the context of other factors that place the child at increased developmental risk, but may not be causally related to the child's behaviour. It is essential to include sufficient information on parental psychiatric symptoms in studies exploring the association between pre-natal cigarette smoke exposure and behavioural disorders.

Methods Children (n = 384) from a prospective population-based birth cohort were assessed at 4 years. The McCarthy Scales of Children's Abilities (MCSA) was administrated. Maternal smoking was measured by questionnaire. Genotyping was conducted for null alleles from GSTM1 and GSTT1. Multivariable linear regression models were used to examine the association between active maternal smoking during pregnancy and MCSA outcomes by GSTM1 and GSTT1 genotypes.

Results Maternal smoking during pregnancy (reporting, yes) was inversely associated with global cognitive score among children having null allele for GSTM1 (β = –4.73, 95% CI –9.45 to –0.02); but not among children with present allele (β = –1.04, 95% CI –7.88 to 5.81) (P for interaction 0.089). The interaction remained after adjusting by post-natal maternal smoking (P = 0.081). The effect was stronger for perceptual-performance (β = –3.68, 95% CI –8.39 to 1.03; P for interaction 0.087), quantitative (β = –7.00, 95% CI –17.39 to 3.39; P for interaction 0.048), verbal (β = –3.63, 95% CI –8.43 to 1.17; P for interaction 0.264) and executive function (β = –4.87, 95% CI –9.55 to –0.20; P for interaction 0.127). No interaction was found for GSTT1.

Conclusions GSTM1 deficiency increases the adverse effects of active maternal smoking during pregnancy on cognition in preschoolers, suggesting a biological interaction between child metabolic genes and tobacco smoke components in detoxification process during foetal neurodevelopment.

Methods A total of 20 936 women with singleton pregnancies were identified within three population-based pregnancy cohorts in Northern Finland (1985–1986) and in Denmark (1984–1987 and 1989–1991). We collected self-reported data on their pre-pregnancy and pregnancy smoking habits and followed the children to school age where teachers and parents rated hyperactivity and inattention symptoms.

Results Children, whose mothers smoked during pregnancy, had an increased prevalence of a high hyperactivity-inattention score compared with children of nonsmokers in each of the cohorts after adjustment for confounders but we found no statistical significant difference between the associations across the cohorts.

Conclusion The estimated association was not strongest in the population with the fewest smokers which does not support the hypothesis that the association is entirely due to genetic confounding.

Methods To examine whether prenatal exposure to acetaminophen reduces the risk of adverse pregnancy outcomes, we used data from the Danish National Birth Cohort. We also examined the combined potential effects of acetaminophen, coffee and tobacco use on pre-eclampsia and preterm birth. The study population consisted of women who provided information on acetaminophen use during pregnancy and gave birth to singletons (n = 98 140). The cohort was linked to the Danish National Hospital Registry and the Medical Birth Registry, which covers all Danish hospitals, miscarriages and births in Denmark.

Results Women using acetaminophen during the third trimester of pregnancy had an increased risk of preterm birth [adjusted hazard ratio (HR) = 1.14, 95% CI: 1.03–1.26]. The risk of preterm birth was increased in mothers with pre-eclampsia (HR = 1.55, 95% CI: 1.16–2.07) but not in women without pre-eclampsia (HR = 1.08, 95% CI: 0.97–1.20). Tobacco smoking and coffee consumption did not modify the effect of acetaminophen in any consistent pattern. No association was found between acetaminophen use and risk of preterm complications, miscarriages, stillbirths, low birth weight or small size for gestational age.

Conclusion Findings do not provide strong support for a change in clinical practice regarding use of acetaminophen during pregnancy, but the increased risk of preterm birth among women with pre-eclampsia should be further investigated.

Methods We carried out a case–control study nested in a large (n = 5337) prospective, multicentre cohort. All cohort women had an interview, examination and venipuncture at 24–26 weeks. Frozen plasma samples in spontaneous preterm births (n = 207) and 444 term controls were analysed for plasma homocysteine, folate, cholesterol (total, low-density lipoprotein and high-density lipoprotein) and thrombin–antithrombin (TAT) complexes. DNA was extracted and analysed for seven gene polymorphisms involved in thrombophilia or folate or homocysteine metabolism. Fresh placentas were fixed, stained and blindly assessed for histologic evidence of infarction and decidual vasculopathy.

Results High (above the median) plasma homocysteine and HDL cholesterol were significantly and independently associated with the risk of spontaneous preterm birth [adjusted odds ratios (OR)s = 1.9 (95% 1.1–3.3) and 0.5 (0.3–0.9), respectively]. A higher proportion of women with high homocysteine concentrations had decidual vasculopathy [(13.0 vs 6.8%; OR = 1.9 (1.1–3.5)], although the positive association between decidual vasculopathy and preterm birth did not achieve statistical significance [OR = 1.5 (0.9–2.7)]. No significant associations were observed with the DNA polymorphisms or with plasma TAT or folate levels.

Conclusions Similar vasculopathic risk factors may underlie preterm birth and adult coronary heart disease and stroke.

Methods In 1982, all 5914 hospital births (over 99% of all deliveries) occurring in Pelotas, Southern Brazil, were identified and studied prospectively on several occasions. In 2004–05, we attempted to trace the whole cohort and information on offspring birthweight was collected. Conditional growth modelling was used to assess the association between offspring birthweight and weight gain from birth to 20 months, and from 20 to 42 months.

Results In 2004–05, we interviewed 4297 subjects, with a follow-up rate of 77.4%. This manuscript includes data from 848 women who had already delivered a child and 525 men who were fathers at the mean age of 23 years. Maternal birthweight, weight and length for age Z-score at 20 months of age were positively associated with next-generation birthweight, whereas paternal variables were not related to the outcome. Conditional growth modelling analyses showed that women whose weight gain in the first 20 months of life was faster than predicted had heavier babies, whereas paternal weight gain was not associated. The association was strongest for mothers whose birthweight for gestational age was in the lowest tertile.

Conclusion Maternal, but not paternal birthweight and weight gain in early childhood are positively associated with next-generation birthweight.

Methods The database used was UBCoS Multigen, which combines existing data on an Uppsala cohort born 1915–29 with information on several subsequent generations. We analysed young men in the third generation with complete information about the earnings of paternal (n = 3577) and maternal (n = 4142) ancestors of the two preceding generations using OLS-regression.

Results On the paternal side, father's and grandfather's, but not grandmother's, earnings predicted cognitive ability and BMI. In the mutually adjusted models, the associations with cognitive ability largely remained for young men whose fathers [b = –0.96 (95% CI: –1.25, –0.66)] and grandfathers [b = –0.60 (–0.87, –0.33)] were poor rather than well-off, whereas for BMI, only the association with grandfather's earnings [b = 0.78 (0.37, 1.19)] persisted. On the maternal side, the mutually adjusted models indicated that the mother's [b = –0.89 (–1.14, –0.65)] and the grandfather's [b = –0.65 (–0.89, –0.41)], but not the grandmother's, earnings were predictive of cognitive ability, whereas only the grandfather's [b = 0.56 (0.18, 0.94)] earnings seemed to be important for BMI.

Conclusions The results suggest that the long arm of the family reaches beyond the second generation in its effect on health. Although this study has only scratched the surface of how health inequalities is reproduced, it suggests that policies that reduce social inequalities may have ramifications across several generations.

Methods We analysed data from a large programmatic cohort across 18 primary care centres providing ART in Lusaka, Zambia. Patients were stratified into three categories based on MPR-calculated adherence over the first 12 months: optimal (≥95%), suboptimal (80–94%) and poor (<80%).

Results Overall, 27 115 treatment-naïve adults initiated and continued ART for ≥12 months: 17 060 (62.9%) demonstrated optimal adherence, 7682 (28.3%) had suboptimal adherence and 2373 (8.8%) had poor adherence. When compared with those with optimal adherence, post-12-month mortality risk was similar among patients with sub-optimal adherence [adjusted hazard ratio (AHR) = 1.0; 95% CI: 0.9–1.2] but higher in patients with poor adherence (AHR = 1.7; 95% CI: 1.4–2.2). Those <80% MPR also appeared to have an attenuated CD4 response at 18 months (185 cells/µl vs 217 cells/µl; P < 0.001), 24 months (213 cells/µl vs 246 cells/µl; P < 0.001), 30 months (226 cells/µl vs 261 cells/µl; P < 0.001) and 36 months (245 cells/µl vs 275 cells/µl; P < 0.01) when compared with those above this threshold.

Conclusions MPR was predictive of clinical outcomes and immunologic response in this large public sector antiretroviral treatment program. This marker may have a role in guiding programmatic monitoring and clinical care in resource-constrained settings.

Methods A 1:1 matched case–control study was conducted in two ‘fever’ hospitals in Cairo. Acute hepatitis B cases were patients with acute hepatitis, positive HBs antigen, and high anti-HBc IgM titres. Control subjects were acute hepatitis A patients (positive anti-HAV IgM) or relatives of patients diagnosed with acute hepatitis C, identified at the same hospitals, with no past HBV infection (negative anti-HBc) and matched to cases on the same age and sex. Conditional logistic regression was used to identify factors associated with acute hepatitis B.

Results Between April 2002 and June 2006, 233 cases and 233 controls were recruited to the study. In multivariate analysis, factors associated with an increased HBV risk in males were illiteracy [odds ratio (OR) = 6.1, 95% confidence interval (CI) = 2.8–13.1], shaving at barbers (OR = 2.1, 95% CI = 1.1–3.9) and injecting drug use (IDU) (OR = 3.4, 95% CI = 1.0–11.4). In females, factors associated with an increased HBV risk were illiteracy (OR = 2.2, 95% CI = 1.0–5.0), recent (<1 year) marriage (OR = 42.0, 95% CI = 3.8–463.9 compared with single women) and giving birth (OR = 3.7, 95% CI = 1.0–13.9).

Conclusion In this study, HBV transmission took place primarily in the community, whether as a result of recent marriage (presumably first sexual intercourse), shaving at barbershops or IDU, and was more common among illiterates. Health promotion campaigns should be carried out to increase awareness about community transmission of HBV. In addition to routine immunization for infants and other populations, premarital screening might be useful to identify at-risk spouses in order to propose targeted immunization.

Methods We used a dynamic time-to-event analysis of data from two large child studies in low-income settings in Ghana and Brazil, with the cumulative diarrhoea prevalence over 2 weeks as the exposure and severe ALRI as outcome. The analysis was adjusted for baseline risk of ALRI and diarrhoea, seasonality and age.

Results The child population from Ghana had a much higher risk of diarrhoea, malnutrition and death than the children in Brazil. In the data from Ghana, every additional day of diarrhoea within 2 weeks increased the risk of ALRI by a factor of 1.08 (95% CI 1.00–1.15). In addition, we found a roughly linear relationship between the number of diarrhoea days over the last 28 days and the risk of ALRI. In the Ghana data, 26% of ALRI episodes may be due to recent exposure to diarrhoea. The Brazilian data gave no evidence for an association between diarrhoea and ALRI.

Conclusion Diarrhoea may contribute substantially to the burden of ALRI in malnourished child populations.

Methods We conducted a cross-sectional study of subjects ≥45 years of age, who were tested for seropositivity to CMV, HSV-1 or both pathogens and assessed for cardiovascular disease history in the National Health and Nutrition Examination Survey III. Cardiovascular disease history was defined as history of stroke, heart attack and/or congestive heart failure and SEP as education level.

Results SEP was associated with CMV, HSV-1 and seropositivity to both pathogens. CMV seropositivity was associated with cardiovascular disease history even after adjusting for confounders as well as SEP. The odds of reporting a history of cardiovascular disease for those with less than a high school education compared with those with more than a high school education decreased by 7.7% after adjusting for CMV (Sobel mediation test for CMV, P = 0.0006). In contrast, neither seropositivity to HSV-1 nor to both pathogens was associated with cardiovascular disease history after adjusting for SEP.

Conclusions Persistent pathogens such as CMV infection may explain a portion of the relationship between SEP and cardiovascular disease in the United States. Further studies examining additional pathogens and sociobiological mechanisms are warranted.

Methods Use of standardized 24-h sodium excretion estimates for adults from the international INTERSALT (1985–87) and INTERMAP (1996–99) studies, and recent dietary and urinary sodium data from observational or interventional studies—identified by a comprehensive search of peer-reviewed and ‘grey’ literature—presented separately for adults and children. Review of methods for the estimation of sodium intake/excretion. Main food sources of sodium are presented for several Asian, European and Northern American countries, including previously unpublished INTERMAP data.

Results Sodium intakes around the world are well in excess of physiological need (i.e. 10–20 mmol/day). Most adult populations have mean sodium intakes >100 mmol/day, and for many (particularly the Asian countries) mean intakes are >200 mmol/day. Possible exceptions include estimates from Cameroon, Ghana, Samoa, Spain, Taiwan, Tanzania, Uganda and Venezuela, though methodologies were sub-optimal and samples were not nationally representative. Sodium intakes were commonly >100 mmol/day in children over 5 years old, and increased with age. In European and Northern American countries, sodium intake is dominated by sodium added in manufactured foods (~75% of intake). Cereals and baked goods were the single largest contributor to dietary sodium intake in UK and US adults. In Japan and China, salt added at home (in cooking and at the table) and soy sauce were the largest sources.

Conclusions Unfavourably high sodium intakes remain prevalent around the world. Sources of dietary sodium vary largely worldwide. If policies for salt reduction at the population level are to be effective, policy development and implementation needs to target the main source of dietary sodium in the various populations.

Methods We performed a pooled analysis of 15 case–control studies (5700 melanoma cases and 7216 controls), correlating patterns of sun exposure, sunburn and solar keratoses (three studies) with melanoma risk. Pooled odds ratios (pORs) and 95% Bayesian confidence intervals (CIs) were estimated using Bayesian unconditional polytomous logistic random-coefficients models.

Results Recreational sun exposure was a risk factor for melanoma on the trunk (pOR = 1.7; 95% CI: 1.4–2.2) and limbs (pOR = 1.4; 95% CI: 1.1–1.7), but not head and neck (pOR = 1.1; 95% CI: 0.8–1.4), across latitudes. Occupational sun exposure was associated with risk of melanoma on the head and neck at low latitudes (pOR = 1.7; 95% CI: 1.0–3.0). Total sun exposure was associated with increased risk of melanoma on the limbs at low latitudes (pOR = 1.5; 95% CI: 1.0–2.2), but not at other body sites or other latitudes. The pORs for sunburn in childhood were 1.5 (95% CI: 1.3–1.7), 1.5 (95% CI: 1.3–1.7) and 1.4 (95% CI: 1.1–1.7) for melanoma on the trunk, limbs, and head and neck, respectively, showing little variation across latitudes. The presence of head and neck solar keratoses was associated with increased risk of melanoma on the head and neck (pOR = 4.0; 95% CI: 1.7–9.1) and limbs (pOR = 4.0; 95% CI: 1.9–8.4).

Conclusion Melanoma risk at different body sites is associated with different amounts and patterns of sun exposure. Recreational sun exposure and sunburn are strong predictors of melanoma at all latitudes, whereas measures of occupational and total sun exposure appear to predict melanoma predominately at low latitudes.

Methods The Whitehall II study of socioeconomic inequalities in health provided response status from five data collection surveys; Phase 1 (1985–88, n = 10 308), Phase 5 (1997–99, n = 6533), and all-cause mortality to 2006. Odd-numbered phases included a medical examination in addition to a questionnaire.

Results Non-response to baseline and to follow-up phases that included a medical examination was associated with a doubling of the mortality hazard in analyses adjusted for age and sex. Compared with complete responders, responders who missed one or more phases, but completed the last possible phase before they died, had a 38% excess risk of mortality. However, those who missed one or more phases including the last possible phase before death had an excess risk of 127%. There was no evidence that these associations differed by socioeconomic position.

Conclusion In studies with repeat data collections, non-response to follow-up is associated with the same doubling of the mortality risk as non-response to baseline; an association that is not modified by socioeconomic position.

Methods In this population-based prospective study, 1529 employees from several large Belgian companies were followed for a median observation period of 6.6 years with respect to the onset of the MetS and its separate components.

Results At baseline, 309 men (20.2%) were rotating shift workers. The MetS incidence rate in these shift workers (60.6 per 1000 person-years) was increased in comparison with day workers (37.2 per 1000 person-years) with an odds ratio (95% CI) of 1.77 (1.34–2.32). Multivariate adjustment for potential lifestyle and work-related confounders did only marginally affect the strength of the association. The risk for the development of MetS gradually increased independently with accumulated years of shift work. Rotating shift work not only had an impact on MetS as a cluster of conditions but on each of its individual components as well.

Conclusions Hence, prospective evidence was found that rotating shift work increases the risk for developing the MetS over a period of 6 years.

Methods From 2003 to 2004, 1003 patients were repeatedly clinically examined. On every clinical visit (on average 5.8 times), blood EDTA-plasma samples were collected. High sensitivity C-reactive protein (CRP), interleukin (IL)-6 and fibrinogen concentrations were measured based on standardized procedures. Dietary habits were evaluated through a semi-quantitative Food Frequency Questionnaire (FFQ), whereas adherence to the Mediterranean diet was assessed by a diet score.

Results A protective effect of adherence to the Mediterranean diet was found. For each unit of increasing adherence to the Mediterranean diet score there was a reduction of 3.1% in the average CRP levels (95% CI 0.5–5.7%) and of 1.9% in the average IL-6 levels (95% CI 0.5–3.4%) after adjusting for centre, age, sex, body mass index, physical activity, smoking status, diabetes and medication intake. No significant association was observed between the diet score and fibrinogen levels. Moderate intake of red wine (1–12 wine glasses per month) was associated with lower levels of CRP, IL-6 and fibrinogen.

Conclusions Adherence to the traditional Mediterranean diet was associated with a reduction of the concentrations of inflammatory markers in MI survivors. This may, in part, explain the beneficial effects of this diet on various chronic diseases such as atherosclerosis and cancer, and expands its role to secondary prevention level.

Methods Men aged 47–67 years had lung function measured between 1984 and 1988 and repeated between 2002 and 2004 (n = 827) as well as having carotid-femoral pulse wave velocity (PWV) measured.

Results Both forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) in mid-life and later life were inversely associated with PWV (P < 0.0001) but mid-life measures were stronger predictors. Only mid-life measures remained predictors after mutual adjustment (FEV₁ mid-life β coeff. –0.65, 95% CI –1.04, –0.26, P < 0.0001; FVC mid-life β coeff. –0.52, 95% CI –0.82, –0.23, P < 0.0001). Adjustment for smoking status, early life, inflammatory and metabolic factors in sub-groups did not markedly change the associations.

Conclusions Mid-life lung function is a stronger risk factor than in later life for arterial stiffness in men. It is possible that developmental factors influence both lung function and arterial stiffness. Lung function assessment in mid-life may identify individuals at greater risk of their future cardiovascular disease.

Methods Retrospective 5-year study of two fixed cohorts, homeless adults and an age- and sex-matched random sample of the local non-homeless population in Greater Glasgow National Health Service Board area for comparison.

Results Over 5 years of observation, 1.7% (209/12 451) of the general population and 7.2% (457/6323) of the homeless cohort died. The hazard ratio of all-cause mortality in homeless compared with non-homeless cohorts was 4.4 (95% CI: 3.8–5.2). After adjustment for age, sex and previous hospitalization, homelessness was associated with an all-cause mortality hazard ratio of 1.6 (95% CI: 1.3–1.9). Homelessness had differential effects on cause-specific mortality. Among patients who had been hospitalized for drug-related conditions, the homeless cohort experienced a 7-fold increase in risk of death from drugs compared with the general population.

Conclusions Homelessness is an independent risk factor for deaths from specific causes. Preventive programmes might be most effectively targeted at the homeless with these conditions.