Fujiwara Takeo, Kawachi Ichiro
Centre for Community Child Health Research, Child and Family Research Institute, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.
Am J Prev Med. 2008 Aug;35(2):139-44. doi: 10.1016/j.amepre.2008.04.015.
A growing number of studies have suggested a link between social capital and health. However, the association may reflect confounding by factors, such as personality or early childhood environment, that are unmeasured prior common causes of both social capital and health outcomes. The purpose of this study was to investigate the impact of social capital on physical and mental health among adult twins in the U.S.
A cross-sectional national survey of twins within the National Survey of Midlife Development in the U.S. (MIDUS), 1995--1996 was analyzed in 2007. The study population included 944 twin pairs (37.2% monozygotic [MZ] and 62.8% dizygotic [DZ]). Data were obtained on individual-level social capital variables (social trust, sense of belonging, volunteer activity, and community participation); health outcomes (perceived physical and mental health, depressive symptoms and major depression); and individual covariates (age, gender, race, education, working status, and marital status). A fixed-effects model was used to examine health status among twin pairs who were discordant on levels of social capital.
In the individual data analysis, social trust, sense of belonging, and community participation were each significantly associated with health outcomes. In the fixed-effects model, physical health remained significantly positively associated with social trust among MZ and DZ twins. However, major depression was not associated with social capital.
The present study is the first to find the independent positive effect of social trust on self-rated physical health using fixed-effects models of twin data. The results suggest that the association between social capital and physical health status is not explained by unobserved confounds, such as personality or early childhood environment.
越来越多的研究表明社会资本与健康之间存在联系。然而，这种关联可能反映了诸如个性或童年早期环境等因素的混杂作用，这些因素是社会资本和健康结果未测量的先前共同原因。本研究的目的是调查社会资本对美国成年双胞胎身心健康的影响。
2007年对1995 - 1996年美国中年发展全国调查（MIDUS）中的双胞胎进行了横断面全国性调查分析。研究人群包括944对双胞胎（37.2%为同卵双胞胎[MZ]，62.8%为异卵双胞胎[DZ]）。获取了个体层面的社会资本变量（社会信任、归属感、志愿活动和社区参与）、健康结果（感知到的身心健康、抑郁症状和重度抑郁症）以及个体协变量（年龄、性别、种族、教育程度、工作状态和婚姻状况）的数据。使用固定效应模型检查在社会资本水平上不一致的双胞胎对的健康状况。
在个体数据分析中，社会信任、归属感和社区参与均与健康结果显著相关。在固定效应模型中，同卵和异卵双胞胎的身体健康与社会信任仍显著正相关。然而，重度抑郁症与社会资本无关。
本研究首次使用双胞胎数据的固定效应模型发现社会信任对自评身体健康有独立的积极影响。结果表明，社会资本与身体健康状况之间的关联不能由未观察到的混杂因素（如个性或童年早期环境）来解释。
