Factors Associated with the Effectiveness of a Telephone-Based Nursing Strategy for Enhancing Medication Adherence in Schizophrenia

A post hoc analysis was made to identify factors associated with success following a 4-month telephone-based strategy for enhancing adherence to antipsychotic treatment in schizophrenia. A total of 928 stable outpatients were randomized to receive a monthly telephone call provided by a nurse or routine clinical care. Logistic regression with a backward stepwise procedure was used. A higher percentage of patients in the intervention group (25.7%, n=109) improved adherence at the end of the study compared with the control group (16.8%, n=74) (p=0.0013). The intervention was significantly associated with adherence improvement in those patients with a previous negative attitude towards medication (OR=4.7, 95% CI =2.4-9.0, p<0.0001). A slight concordance was obtained between adherence improvement and improvement in patient perception of treatment (kappa=0.21; 95% CI=0.15-0.27). The identification of factors related to the effectiveness of a specific intervention would offer clinicians the opportunity to more adequately select patients who are eligible for such intervention.