Medication adherence and quality of life among Nigerian outpatients with schizophrenia

The aim of this study was to examine medication adherence among outpatients with schizophrenia in relation to their subjective quality of life and other sociodemographic, clinical and service related factors.

Three hundred and thirteen consecutive outpatient clinic attendees with a Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) diagnosis of schizophrenia confirmed with the Structured Clinical Interview for Diagnosis were recruited for the study. Respondents were interviewed using a questionnaire evaluating sociodemographic, medication, illness and clinic attendance related variables. Medication adherence was assessed using the Morisky medication adherence questionnaire. Participants also completed the World Health Organization Quality of Life Scale-BREF questionnaire as a measure of their subjective quality of life, while severity of illness was measured using the Brief Psychiatric Rating Scale (BPRS).

Overall, 40.3% of the respondents were medication nonadherent. Medication adherent respondents significantly reported their perceived social support as "good" (P=.006), took significantly fewer number of medications (P≤.001), had higher medication use recall scores (P≤.001), had lower total BPRS scores (P=.001) and were "very satisfied" with their outpatient care (P=.002). Independent predictors of medication nonadherence were BPRS score [odds ratio (OR)=1.08, 95% confidence interval (95% CI)=1.03-1.13], outpatient clinic default (OR= 4.97, 95% CI=2.59-9.53) and moderate satisfaction with outpatient care (OR=2.78, 95% CI=1.47-5.24). Medication nonadherence was significantly associated with lower scores on all domains and facets of quality of life.

Medication nonadherence is common among outpatients with schizophrenia and is associated with poor quality of life. Clinicians' awareness of the risk factors for medication nonadherence early in patients' management may significantly improve treatment outcomes, including patients' quality of life.