Objective: To identify factors affecting adherence to medication, a subjective questionnaire survey was administered to schizophrenia patients regarding the prescribed antipsychotic formulations.
Methods: We evaluated the patients' satisfaction and dissatisfaction with prescribed antipsychotic formulations, and patients answered the Drug Attitude Inventory-10 Questionnaire (DAI-10). Inclusion criteria for patients are as follows: age between 20 and 75 years and taking antipsychotic agents containing the same ingredients and formulations, for at least 1 month.
Results: In total, 301 patients answered the questionnaire survey. Tablets were found to be the most commonly used antipsychotic formulations among schizophrenia patients (n = 174, 57.8%), followed by long-acting injections (LAIs, n = 93, 30.9%). No significant differences in the formulation satisfaction level and DAI-10 scores were observed between all formulations. Formulations, except for LAI, were selected by physicians in more than half of the patients. Patients who answered "Decided by consultation with physicians" had significantly higher satisfaction levels and DAI-10 scores compared to those who answered "Decided by physicians" (4.11 ± 0.77 vs. 3.80 ± 1.00, p = 0.0073 and 6.20 ± 3.51 vs. 4.39 ± 4.56, p < 0.001, respectively). Satisfaction levels moderately correlated with DAI-10 scores (r = 0.48, p < 0.001).
Conclusion: No formulation had a high satisfaction level in all patients, and it is important to be reflect the patients' individual preferences in pharmacotherapy. Shared decision-making in the selection of the formulations is seen to be useful for improving medication adherence.
Keywords: Antipsychotic agents; Drug formulation; Medication adherence; Patient satisfaction; Schizophrenia; Surveys and questionnaires.