Elliott P
Department of Public Health and Policy, London School of Hygiene and Tropical Medicine, UK.
Ciba Found Symp. 1993;175:219-29; discussion 229-33.
Epidemiology is the study of the distribution and determinants of health and disease in human populations. Epidemiology on a global scale is severely constrained by the lack of data. In many countries, there are no comprehensive data on mortality or basic demographic data. Where data are available, findings on the relationship of environment to health across countries need to be interpreted with caution. For example, there is well-known variation in standards of medical practice and diagnosis, and in certification and coding, but there are also large differences in diet, the social environment and lifestyle--all of which strongly predict disease incidence. Inappropriate inference concerning aetiology made from such broad-scale studies may result in what has been termed the 'ecological fallacy'. A complementary approach is to collect and analyse data in standardized fashion as part of international collaborative studies. These can offer some important advantages over the more conventional single-centre design. Recent advances have meant that studies of environment and health can now--in some countries--be carried out using routine data at the small area level. Although problems of interpretation remain, they are generally less severe than in broad-scale studies. Examples of this approach are given.
流行病学是研究人群中健康与疾病的分布及其决定因素。全球范围内的流行病学研究因缺乏数据而受到严重限制。在许多国家，没有关于死亡率的全面数据或基本人口数据。即便有数据，对各国环境与健康关系的研究结果也需谨慎解读。例如，医疗实践和诊断标准、认证与编码存在众所周知的差异，饮食、社会环境和生活方式也有很大不同，而所有这些都对疾病发病率有强烈预测作用。基于此类大规模研究对病因进行不恰当推断可能会导致所谓的“生态学谬误”。一种补充方法是作为国际合作研究的一部分，以标准化方式收集和分析数据。与更传统的单中心设计相比，这些研究能提供一些重要优势。最近的进展意味着现在在一些国家可以利用小区域层面的常规数据开展环境与健康研究。尽管解读问题依然存在，但通常比大规模研究中的问题要轻。文中给出了这种方法的实例。
