Logan S, Spencer N
Department of Epidemiology and Biostatistics, Institute of Child Health, London.
Arch Dis Child. 1996 Feb;74(2):176-9. doi: 10.1136/adc.74.2.176.
It seems clear that parental smoking is harmful, although the magnitude of its effect may be smaller than sometimes suggested. However, smoking and other behaviours detrimental to health must be seen within a social and historical context. Individuals are not 'free choosing actors' and their behaviour is determined, at least in part, by their social and environmental circumstances. Smoking might better be regarded as a 'proximal' cause. 'Proximal' causes such as infectious or toxic agents are themselves subject to 'causes of causes' which are the determinants of exposure to these agents. Smoking may act as the 'proximal' cause, directly harming the fetus, but is itself caused by factors in the social and environmental circumstances. The complexity of the relationship between social and environmental circumstances, health related behaviours, and adverse outcomes cannot be resolved by the search for single causative agents. As Rutter points out, in order to begin to understand causal complexity 'it is necessary to examine distal causal relationships in the form of chains and of linked sequences involving several different, relatively short-term effects or operations' (p 2). Health promotion programmes sensitive to social context avoid 'victim blaming' and acknowledge that it is not enough to exhort mothers to 'stop smoking before and during pregnancy because this will harm your baby' (p 99). Mothers know that smoking can harm themselves and their babies and the vast majority want to give up. Their choice is limited by their social circumstances, and failure to recognise this has ensured the failure of health promotion initiatives aimed at smoking reduction during pregnancy. There are limitations in the techniques available to control for confounding in multivariate analysis and results must be interpreted with caution. Misinterpretation can lead to overemphasis of the role of single factors, diverting attention from complex pathways. While health related behaviours may be a 'proximal' cause of ill health, there is a duty on researchers, health promoters, and health policy makers to take account of the complex causal pathways in which these 'proximal' causes lie.
显然，父母吸烟是有害的，尽管其影响程度可能比有时认为的要小。然而，吸烟及其他有害健康的行为必须放在社会和历史背景中去看待。个体并非“自由选择的行为者”，他们的行为至少部分地由其社会和环境状况所决定。吸烟或许更宜被视为一个“近端”原因。诸如感染源或有毒物质等“近端”原因本身又受制于“原因的原因”，即接触这些物质的决定因素。吸烟可能作为“近端”原因直接损害胎儿，但它本身又是由社会和环境状况中的因素所致。社会和环境状况、与健康相关的行为以及不良后果之间关系的复杂性，无法通过寻找单一致病因素来解决。正如鲁特所指出的，为了开始理解因果关系的复杂性，“有必要以链条和涉及几个不同的、相对短期的影响或作用的关联序列的形式来审视远端因果关系”（第2页）。对社会背景敏感的健康促进项目避免“指责受害者”，并认识到仅仅告诫母亲“在怀孕前和怀孕期间不要吸烟，因为这会伤害你的宝宝”是不够的（第99页）。母亲们知道吸烟会伤害自己和宝宝，绝大多数人都想戒烟。她们的选择受到社会状况的限制，而未能认识到这一点导致了旨在减少孕期吸烟的健康促进举措的失败。在多变量分析中用于控制混杂因素的现有技术存在局限性，对结果的解释必须谨慎。错误解读可能导致过度强调单一因素的作用，从而将注意力从复杂的因果路径上转移开。虽然与健康相关的行为可能是健康不良的“近端”原因，但研究人员、健康促进者和健康政策制定者有责任考虑这些“近端”原因所处的复杂因果路径。
