Introduction: Health effects of social isolation are well-studied at older age, in English-speaking countries, for individual health conditions, and based on unidimensional measures of isolation. Hardly any evidence exists for younger ages, for continental European and particularly German-speaking countries and based on multidimensional measures of isolation. This study therefore aimed to examine prevalence rates and associations of social isolation with various health conditions and behaviors in the entire Swiss population and across different age groups.
Methods: Nationally representative cross-sectional data from the Swiss Health Survey collected in 2012 were used and analyzed. The study sample covered 21,597 randomly selected adolescents and adults living in Switzerland and aged 15 and older. A multifactorial five-item social integration index was used to assess social disconnectedness and perceived isolation.
Results: Social isolation has been found to steadily increase with age and almost consistently to be strongly associated with poor health conditions and unfavorable behaviors across all ages. Nearly a quarter of the general population could be categorized as either only partly integrated or even poorly integrated and largely isolated. The socially isolated people independent of their age showed strongly elevated relative risks of poor self-rated health (aOR = 4.0), musculoskeletal disorders (aOR = 2.8), moderate to severe depression (aOR = 11.5), and multiple health problems (aOR = 5.0). They were also found to be at comparably high risk of behaving unhealthy with regard to physical inactivity (aOR = 2.2), poor diet (aOR = 1.9) and use of psychotropic medications (aOR = 3.6). Although prevalence rates of poor health conditions and behaviors differed greatly between the studied age groups, strong associations and clear dose-response relationships have been found separately for all age groups and particularly for the youngest. A fairly weak or no association at all (depending on the age group) with the degree of social integration was observed only for daily smoking.
Conclusions: Social isolation may be less prevalent at younger ages, but is then even more strongly associated with poor health conditions and behaviors than at older ages.