An evaluation of non-adherence to pharmacotherapy for chronic diseases and socioeconomic inequalities in Brazil

ABSTRACT: Objective: To evaluate non-adherence to pharmacotherapy for chronic diseases and to investigate the existence of socioeconomic inequalities related to this outcome in Brazil. Methods: This was a cross-sectional study based on data from the National Survey on Access, Use and Promotion of the Rational Use of Medicines (PNAUM). The study population corresponded to individuals aged 18 years or older with a medical diagnosis of at least one chronic disease and an indication for pharmacological treatment. The dependent variable was non-adherence to chronic disease pharmacotherapy measured by less than 80% adherence to drug therapy. Socioeconomic inequality related to non-adherence was assessed by absolute (SII) and relative (RII) inequality indices, calculated by logistic regression analyses. Results: The prevalence of non-adherence to pharmacotherapy in Brazil was 20.2%, ranging from 17.0 to 27.8% between regions. Furthermore, this study revealed absolute and relative socioeconomic inequalities in non-adherence to pharmacotherapy of chronic diseases in Brazil (SII = -7.4; RII = 0.69) and the Northeast (SII = -14.0; RII = 0.59) and Center West (SII = -20.8; RII = 0.38) regions. The probability of non-adherence to pharmacotherapy in Brazil was higher among individuals with worse socioeconomic status. Conclusion: The findings of the present study indicate the need for the restructuring and strengthening of public policies aimed at reducing socioeconomic inequalities, in order to promote equity in adherence to the pharmacotherapy associated with chronic diseases.