Maheswaran Ravi, Strachan David P, Dodgeon Brian, Best Nicola G
Public Health GIS Unit, School of Health and Related Research, The University of Sheffield, Sheffield S1 4DA, UK.
Int J Epidemiol. 2002 Apr;31(2):375-82.
Geographical variation in mortality is influenced by factors operating in early life and in adulthood. The relative contributions of these factors may be examined by comparing the extent to which adult mortality is related to places of residence in early life and at death. We describe a population-based case-control design, in which all deaths are used as cases and the Office for National Statistics (ONS) Longitudinal Study (LS) survivors are used as controls.
Cases were all deaths from stomach cancer and stroke in England and Wales 1993-1995 amongst people born between January 1930 and September 1939 and for whom place of enumeration in 1939 could be imputed from the first three characters of their National Health Service number. Controls were all LS members born in the same period, enumerated in the 1991 census, resident in England and Wales in mid-1994 and for whom place of enumeration in 1939 could be similarly imputed. Logistic regression was used, adjusting for birth year, sex and social class. A previous mapping exercise by ONS generated comparable geographical units (counties) for 1939 enumeration and area of residence in 1991 or at death. 'Non-migrant' (i.e. 1939 'county' the same as county in 1991 or at death) case:control ratios were calculated to indicate background mortality risk in counties, with adjustment for imprecision using Bayesian smoothing methods. These ratios were then used in modelling risk for inter-county migrants.
There were 2590 stomach cancer and 7778 stroke deaths and 28,400 men and 28,180 women as controls. For men, 64%, 61% and 67% of stomach cancer deaths, stroke deaths and controls respectively could be assigned a county of enumeration in 1939. The corresponding percentages for women were 76%, 72% and 75%. For stomach cancer, after adjustment for county of enumeration in 1939, a significant association with the non-migrant case:control ratio for county of residence in 1991 or at death was observed (P= 0.010), indicating an association between current area of residence and stomach cancer mortality. There was no evidence of an independent effect of county of enumeration in 1939. For stroke, there was a highly significant trend in relation to 1939 county (P = 0.0004)and a less significant association with county of residence in 1991 or at death(P = 0.016).
The method described is able to detect the effect of place of residence in early life on geographical variation in adult mortality and will be useful for investigating specific characteristics of areas of enumeration in 1939 in relation to subsequent risk of mortality from a range of diseases.
死亡率的地理差异受到早年和成年期各种因素的影响。通过比较成年死亡率与早年居住地和死亡时居住地的关联程度，可以研究这些因素的相对贡献。我们描述了一种基于人群的病例对照设计，其中所有死亡病例作为病例组，英国国家统计局（ONS）纵向研究（LS）的幸存者作为对照组。
病例为1993 - 1995年在英格兰和威尔士死于胃癌和中风的所有人，这些人出生于1930年1月至1939年9月之间，并且可以根据其国民健康服务号码的前三个字符推算出1939年的普查地点。对照组为同期出生、在1991年人口普查中登记、1994年年中居住在英格兰和威尔士且同样可以推算出1939年普查地点的所有LS成员。使用逻辑回归，并对出生年份、性别和社会阶层进行了调整。ONS之前的一项绘图工作生成了1939年普查和1991年或死亡时居住地区可比的地理单位（县）。计算“非移民”（即1939年“县”与1991年或死亡时的县相同）的病例对照比，以表明各县的背景死亡风险，并使用贝叶斯平滑方法对不精确性进行调整。然后将这些比值用于模拟县际移民的风险。
有2590例胃癌死亡和7778例中风死亡，以及28400名男性和28180名女性作为对照组。对于男性，分别有64%、61%和67%的胃癌死亡病例、中风死亡病例和对照组可以确定1939年的普查县。女性的相应百分比分别为76%、72%和75%。对于胃癌，在调整了1939年的普查县后，观察到与1991年或死亡时居住县的非移民病例对照比存在显著关联（P = 0.010），表明当前居住地区与胃癌死亡率之间存在关联。没有证据表明1939年普查县有独立影响。对于中风，与1939年的县有高度显著的趋势（P = 0.0004），与1991年或死亡时居住县的关联不太显著（P = 0.016）。
所描述的方法能够检测早年居住地对成年死亡率地理差异的影响，并且将有助于研究1939年普查地区的特定特征与随后一系列疾病死亡风险的关系。
