IMPACT OF SOCIAL ISOLATION ON MORTALITY AND MORBIDITY

Abstract

BACKGROUND: Social isolation (SI) has been seen as an emerging socioeconomic factor that negatively affects health. A considerable body of research has found that SI is associated with increased risk of all-cause mortality. However, the magnitude of the association varies in different studies. Besides that, these studies were conducted mainly in high-income countries. METHODS: We conducted a systematic review and meta-analysis to examine the effect size of SI on mortality. Also, we examined the associated mortality risk using data from the Prospective Urban and Rural Epidemiology (PURE) study of over 140,000 middle-aged adults from 21 countries with different income levels. RESULTS: Our systematic review and meta-analysis showed that the pooled hazard ratio of SI for all-cause mortality was 1.37 (95% confidence interval (CI) 1.28-1.46). The PURE study showed that the hazard ratio of SI for all-cause mortality was 1.26 (95% CI 1.16-1.36). Similar associations of SI with cardiovascular- and non-cardiovascular mortality as well as with incident diseases including stroke, cardiovascular disease, and injury were observed. The associations between SI and health outcomes were observed in diverse populations with different social structures and different country income levels. CLINICAL IMPLICATIONS: The impact of SI on mortality would be expected to be greater in the future as the number of people with SI is projected to increase with population ageing in most societies. Our findings can be used by public health providers and policy makers to develop targeted strategies to reduce the risks associated with SI.