Subjective reasons for adherence to psychotropic medication and associated factors among older adults with schizophrenia

RationaleThere are limited data examining subjective influences on medication adherence among older persons with schizophrenia. The subjective reasons for adherence to antipsychotic medication and associated clinical and psychosocial factors in this population are examined.MethodsThe sample consisted of 198 community dwelling persons aged ≥ 55 who developed schizophrenia before age 45. Using the Rating of Medication Influences Scale (ROMI), a principal component factor analysis with varimax rotation yielded three subscales: Medication Affinity and Prevention, Influence of Others, and Impact of Authority. These subscales were dichotomized into high and low based on a median split. We also created an ordinal High Adherence measure based on the summed scores of each person's three dichotomized ROMI subscales. A modified Health Belief Model was used to examine the association between 18 predictor variables and the ROMI subscales and the adherence scale.ResultsThe mean subscale rankings were Medication Affinity and Prevention > Impact of Authority > Influence of Others. In logistic regression, lower education, more side effects, higher depression scores, and more mental health services were associated with higher scores on Influence of Others subscale. More side effects and more entitlements were associated with higher scores on the Medication Affinity and Prevention subscale. The Impact of Authority subscale had no significant associations. More side effects and higher depression scores were associated with higher scores on High Adherence measure.ConclusionWe identified a three-dimensional model for explaining the subjective reasons for medication adherence in older persons with schizophrenia. Our findings suggest that cognitive approaches and use of authority figures may be useful for promoting adherence in older adults. Independent variables associated with these subscales may provide guidance for improving adherence in this population.