RESUMEN
OBJECTIVES: To estimate the proportion of patients with drug-related morbidities (DRMs), DRM preventability, and the cost of illness of the DRMs in Brazil. METHODS: We used the decision-analytic model initially developed by Johnson and Bootman (Drug-related morbidity and mortality. A cost-of-illness model. J Manag Care Pharm 1996;2:39-47), which was adapted to the reality of the present study. A hypothetical cohort of patients in ambulatory care setting was simulated considering the perspective of the Brazilian public health system. Direct costs related to health care were obtained from the national databases, and the probability of occurrence of DRMs was established by a panel of clinical experts. Sensitivity analyses were conducted. RESULTS: An estimated 59% ± 14% of all patients assisted by the health system suffer some DRMs. Given these cases, 53% ± 18% were considered preventable. The average cost of managing a patient with any DRM was US $155. The cost of illness of the DRMs in Brazil would account for nearly US $18 billion (US $9-$27 billion) (best and worst case scenarium) annually. This amount is 5 times higher than what the Ministry of Health spends to guarantee free medicines in Brazil. Hospitalizations and long-term stays in hospital correspond to 75% of this cost. The sensitivity analysis showed that the model is sensitive to variations in these two outcomes. CONCLUSIONS: According to the model, a large proportion of patients experience DRM and the economic impact to solve these problems is substantial for the health system. Considering that more than half of these cases are preventable, it could be possible to achieve an enormous saving of resources through actions that improve the process of medication use.