Alexander F E, Leon D A, Cartwright R A
Department of Public Health Sciences, University of Edinburgh Medical School, UK.
Paediatr Perinat Epidemiol. 1996 Oct;10(4):411-7. doi: 10.1111/j.1365-3016.1996.tb00066.x.
To determine whether increased rates of childhood acute lymphoblastic leukaemia (ALL) which had been reported in isolated areas could be attributed to higher proportions of households owning cars, ecological analysis was performed with electoral wards as area units. Previous data were re-analysed using the proportion of households having no car, taken from the 1981 census of England and Wales, as an additional explanatory factor. A specialist registry of haematopoietic malignancies covering one-third of England and Wales (3270 electoral wards) recorded 438 cases of ALL in children diagnosed 1984-89, including 304 in the childhood peak (at ages 1-7 years). Relative risks were derived by Poisson regression of total childhood ALL and at ages 1-7 years for groups of electoral wards classified by isolation and car ownership. Multivariable analyses included adjustment for socio-economic status. No evidence of increased risk of childhood ALL in areas where more households own cars was found. ALL at ages 1-7 years was inversely associated with car ownership (risk in wards with least cars relative to those with most cars = 2.28, 95% CI: 1.12-4.64). The associations with geographic isolation persisted after allowing for car ownership (risks for ALL in young children in isolated relative to built-up areas = 2.19, 95% CI: 1.44-3.33). Levels of car ownership cannot explain the increased rates of childhood ALL which have been observed in isolated areas. No support has been found for a hypothesis relating these excesses to benzene exposure of children transported in cars. The previous explanation for the small area variation of childhood ALL in terms of geographical isolation and interpretation in terms of exposure to common infections continues to be justified.
为了确定在一些孤立地区报告的儿童急性淋巴细胞白血病（ALL）发病率上升是否可归因于拥有汽车的家庭比例较高，以选区为区域单位进行了生态分析。利用1981年英格兰和威尔士人口普查中无车家庭的比例作为额外的解释因素，对先前的数据进行了重新分析。一个覆盖英格兰和威尔士三分之一地区（3270个选区）的造血系统恶性肿瘤专科登记处记录了1984 - 1989年期间诊断出的438例儿童ALL病例，其中304例处于儿童发病高峰期（1 - 7岁）。通过对按孤立程度和汽车拥有情况分类的选区组中儿童ALL总数以及1 - 7岁儿童ALL的泊松回归得出相对风险。多变量分析包括对社会经济地位的调整。未发现有更多家庭拥有汽车的地区儿童ALL风险增加的证据。1 - 7岁儿童的ALL与汽车拥有情况呈负相关（汽车最少的选区相对于汽车最多的选区的风险 = 2.28，95%置信区间：1.12 - 4.64）。在考虑汽车拥有情况后，与地理孤立的关联仍然存在（孤立地区相对于建成区幼儿ALL的风险 = 2.19，95%置信区间：1.44 - 3.33）。汽车拥有水平无法解释在孤立地区观察到的儿童ALL发病率上升情况。未找到支持将这些超额发病率与乘车儿童苯暴露相关的假设的证据。先前关于儿童ALL小区域差异基于地理孤立的解释以及基于接触常见感染的解释仍然合理。
