Social vulnerability as a predictor of mortality and disability: cross-country differences in the survey of health, aging, and retirement in Europe (SHARE).

ABSTRACT

BACKGROUND: Social factors are important for health; the concept of social vulnerability considers them holistically and can be quantified using a social vulnerability index (SVI). AIMS: Investigate the SVI in relation to mortality and disability, independent of frailty, in middle-aged and older European adults, and examine how this relationship differs across countries. METHODS: 18,289 community-dwelling participants 50 years and older from SHARE wave 1 (2004) were included in our sample. A 32-item SVI and a 57-item frailty index were calculated for individuals as the proportion of deficits present out of the total number considered. Countries were grouped based on their social model Nordic (Denmark, Netherlands, Sweden), Continental (France, Austria, Belgium, Germany) and Mediterranean (Greece, Italy, Spain). Outcome measures were 5-year mortality and disability (≥1 dependency with activities of daily living) at wave 4 (2011-2012). RESULTS: High social vulnerability (highest quartile) predicted mortality (HR = 1.25, 95 % CI 1.07-1.45), and disability (OR = 1.36, 95 % CI 1.15-1.62) after controlling for age, sex, baseline disability and frailty level. When analyses were split by social model, social vulnerability remained a significant predictor of mortality for Continental (HR = 1.36, CI 1.05-1.77) and Mediterranean (HR = 1.33, CI 1.03-1.72) countries, but not the Nordic (HR = 1.02, CI 0.76-1.37) countries; the same pattern was observed for disability (Nordic OR = 1.06, CI 0.72-1.55; Continental OR = 1.53, CI 1.20-1.96; Mediterranean OR = 1.58, CI 1.13-2.23). DISCUSSION/CONCLUSIONS: Social vulnerability was a significant predictor of mortality and disability, though when controlling for frailty, this relationship varied by the social model of the country.