IJE Advance Access originally published online on July 31, 2007
International Journal of Epidemiology 2007 36(5):1156; doi:10.1093/ije/dym166
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Childhood leukaemia and socioeconomic status
Epidemiology & Genetics Unit, Department of Health Sciences, University of York, YO10 5DD.
*Corresponding author. E-mail: Alex.Smith{at}egu.york.ac.uk
We thank Borugian et al. for their letter,1 but cannot agree with their interpretation of either study.2,3 Whilst we appreciate the strengths of their investigation—the number of acute lymphoblastic leukaemia (ALL) cases (n = 4024)—this does not alter the fact that their findings may still be artefactual. Their study was predicated on cancer registrations accumulated over the 16-year period 1985–2001—during which time the authors themselves acknowledge that under-registration may have been as high as 5%, occurring more frequently in poorer neighbourhoods. Moreover, primarily due to missing data, a further 3% were excluded from their analyses. Such factors, coupled with other variations, could easily explain why at diagnosis a statistically significant association was observed in the poorest quintile {risk ratio [RR] 0.86 [95% confidence intervals (CI) 0.78–0.95]}—this is the lowest estimate and the one that drives the trend test. Furthermore, the second lowest risk occurred in the second richest quintile [0.90 (0.82–0.99)], suggesting that socio-economic status (SES) is not generally associated with ALL risk in children.
In contrast, the comprehensive nature of the United Kingdom Childhood Cancer Study (www.ukccs.org), together with its complete ascertainment (1578 ALL cases) and representative population-based controls (7663) permitted a far more meticulous investigation of this topic. Two measures of SES were used (based on residential area and parental occupation), and two time-points were examined (birth and diagnosis)—and no patterns or differences emerged. Accordingly, with respect to shedding light on childhood leukaemia pathogenesis, we believe that it's timely to move-on and focus on more plausible determinants.
 |
References |
|---|
 Top References |
|---|
1 Borugian MJ, Spinelli JJ, Mezei G, Wilkins R, McBridge M. Childhood leukaemia and socioeconomic status. [letter]. Int J Epidemiol (2007).
2 Borugian MJ, Spinelli JJ, Mezei G, Wilkins R, Abanto Z, McBride ML. Childhood leukemia and socioeconomic status in Canada. Epidemiology (2005) 16:526–31.[CrossRef][Web of Science][Medline]
3 Smith A, Roman E, Simpson J, Ansell P, Fear NT, Eden T. Childhood leukaemia and socioeconomic status: fact or artefact? A report from the United Kingdom childhood cancer study (UKCCS). Int J Epidemiol (2006) 35:1504–13.
CiteULike 
Connotea 
Del.icio.us What's this?
Related articles in Int. J. Epidemiol.:
- Childhood leukaemia and socioeconomic status
- Marilyn J Borugian, John J Spinelli, Gabor Mezei, Russell Wilkins, and Mary McBride
Int. J. Epidemiol. 2007 36: 929.[Extract] [FREE Full Text]
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||