Interactive effects of social support and social conflict on medication adherence in multimorbid older adults.

With increasing age and multimorbidity, medication regimens become demanding, potentially resulting in suboptimal adherence. Social support has been discussed as a predictor of adherence, but previous findings are inconsistent. The study examines general social support, medication-specific social support, and social conflict as predictors of adherence at two points in time (6 months apart) to test the mobilization and social conflict hypotheses. A total of 309 community-dwelling multimorbid adults (65-85 years, mean age 73.27, 41.7% women; most frequent illnesses: hypertension, osteoarthritis and hyperlipidemia) were recruited from the population-representative German Ageing Survey. Only medication-specific support correlated with adherence. Controlling for baseline adherence, demographics, physical fitness, medication regimen, and attitude, Time 1 medication-specific support negatively predicted Time 2 adherence, and vice versa. The negative relation between earlier medication-specific support and later adherence was not due to mobilization (low adherence mobilizing support from others, which over time would support adherence). Social conflict moderated the medication-specific support to adherence relationship: the relationship became more negative, the more social conflict participants reported. Presence of social conflict should be considered when received social support is studied, because well-intended help might have the opposite effect, when it coincides with social conflict.