Socio-demographic and clinical predictors of medication adherence among psychiatric outpatients in Mozambique: A two-year longitudinal survival analysis

Research on medication adherence among patients with psychiatric illness is particularly sparse in low- and middle-income countries (LMICs). This study examined the relationship between psychiatric medication adherence and clinical and sociodemographic factors in outpatient psychiatric settings in central Mozambique. We conducted a longitudinal study among 803 Psychiatric Outpatients (1,811 total follow-up visits) attending eight healthcare facilities in Mozambique from February 2022 to January 2024. Multivariable linear mixed and non-parametric Kaplan-Meier models were employed to analyze the association between medication and clinical/sociodemographic variables over time. Approximately 93% of patients (N = 729) were non-adherent to their medication at a minimum of one follow-up visit, with a median time in treatment prior to non-adherence of 60 days (mean: 52 days; 95% CI: 51, 53). In the Stratified Cox model, patients aged 56+ had a 33% higher hazard of nonadherence compared to those aged 18-35 (aHR: 1.33; 95% CI: 1.14, 1.55). Patients prescribed amitriptyline had a 56% higher hazard of nonadherence compared to those prescribed carbamazepine (aHR: 1.56; 95% CI: 1.23, 1.98). For every 30 days in treatment, disability scores decreased by an average of 0.13 (95% CI: -0.16 to -0.09) while systolic blood pressure decreased by 0.46 mmHg (95% CI: -0.18 to -0.10) and diastolic blood pressure decreased by 0.15 mmHg (95% CI: -0.23 to -0.06). Currently, the median duration of medication adherence for patients initiating essential psychiatric treatment in Mozambique is 60 days. Patients prescribed amitriptyline and older patients are at a higher risk of non-adherence. Consistent engagement in treatment is linked to lower disability scores and blood pressure. There is an urgent need for research into adherence support strategies, especially for these high-risk groups within Mozambique's mental health patient population.