Retrospective interrupted time series examining hypertension and diabetes medicines usage following changes in patient cost sharing in the 'Farmácia Popular' programme in Brazil.

OBJECTIVES: 'Farmácia Popular' (FP) programme was launched in 2004, expanded in 2006 and changed the cost sharing for oral hypoglycaemic (OH) and antihypertensive (AH) medicines in 2009 and in 2011. This paper describes patterns of usage and continuity of coverage for OH and AH medicines following changes in patient cost sharing in the FP.

STUDY DESIGN: Interrupted time series study using retrospective administrative data.

METHODS: Monthly programme participation (PP) and proportion of days covered (PDC) were the two outcome measures. The open cohort included all patients with two or more dispensings for a given study medicine in 2008-2012. The interventions were an increase in patient cost sharing in 2009 and zero patient cost sharing for key medicines in 2011.

RESULTS: A total of 3.6 and 9.5 million patients receiving treatment for diabetes and hypertension, respectively, qualified for the study. Before the interventions, PP was growing by 7.3% per month; median PDC varied by medicine from 50% to 75%. After patient cost sharing increased in 2009, PP reduced by 56.5% and PDC decreased for most medicines (median 60.3%). After the 2011 free medicine programme, PP surged by 121 000 new dispensings per month and PDC increased for all covered medicines (80.7%).

CONCLUSION: Cost sharing was found to be a barrier to continuity of treatment in Brazil's private sector FP programme. Making essential medicines free to patients appear to increase participation and continuity of treatment to clinically beneficial levels (PDC >80%).