Evaluation of Quality of Life of Primary Health Care Patients in Brazil: Influence of Drug Interactions, Common Mental Disorders, and Use of Psychiatric Medication.

The objectives of this study were to identify the interaction between drug interaction risk, common mental disorders, use of psychiatric medication and quality of life in patients treated in primary health care settings in Brazil. In this quantitative research, 452 patients were interviewed in ten basic Brazilian health units. Sociodemographic and pharmacotherapeutic questionnaires, use of psychiatric medication, prevalence of common mental disorders, and quality of life were utilised. The structural equation model was used to evaluate the relationships among the variables. The prevalence of drug interaction risk was 66.59%. The variables associated with drug interaction risk were polypharmacy and income. The use of psychiatric medication was associated with diagnosis of common mental disorders, income and gender. The use of psychiatric medication and common mental disorders negatively influenced quality of life.