Psychological and cognitive function: Predictors of adherence with cholesterol lowering treatment

BACKGROUND: Failure to adhere to medication regimes is a significant problem in clinical and research settings yet reliable, consistent identification of key psychosocial predictors remains elusive. Studies of mood and personality related to adherence show mixed results-compliance and objectively measured cognitive function are intuitively related but empirical support is lacking. PURPOSE: This study is a secondary analysis to examine the relations between adherence with a medication regime for lowering serum cholesterol and several domains of psychological and cognitive functioning. METHODS: Participants in the initial study completed a measure of personality and a battery of neuropsychological measures at baseline; anxiety and depression were measured at baseline and at 4-week intervals. Medication adherence was tracked with electronic cap monitors for 24 weeks. RESULTS: Only 23% of the sample was fully adherent to medication regimes at least 80% of the time over the 6-month study period. Conscientiousness, according to the Five Factor Theory of Personality, and estimated IQ remained robust predictors of adherence in hierarchical regression analyses. Depression and anxiety, mental flexibility, and visuospatial-constructional ability were less robust but statistically significant (p <.05) correlates of adherence. CONCLUSIONS: Although results of this analysis explain only a portion of the variance in adherence, they demonstrate the importance of trait psychological and cognitive factors in adherence research.