Análisis de persistencia en la toma de medicamentos de uso crónico en usuarios de un programa de reposición periódica de medicamentos sin costo durante dos años en Colombia

Abstract

Introduction: Adherence and persistence to pharmacological therapies are of the most discussed and studied secondary prevention strategies worldwide. In the last decades, the interest in their role in clinical and social outcomes, has increased considerably; therefore, several research had studied the impact of different pro- adherence techniques compared to non-intervention (usual management), these alternatives have been more effective than non-intervention. However, it is still a challenge for clinicians and general society, not just because of the huge amount of health expenditures generated by the lack of adherence and persistence to prescribed medication, but also because of its negative impact on quality of life and mortality of general population.

Objetive: Compare persistence to chronic contraceptives, lipid-lowerings agents, phlebotonic, antihypertensive and antiresorptive drugs in a non-cost periodic drug replacement program according to demographic, dispensing and replacement model variables in adult patients prescribed with these therapies and followed over two years.

Patients and methods: A case-control study nested in a retrospective cohort was conducted from a database of a national periodic drug replacement program without costs, designed to improve drug adherence and persistence in several therapeutic groups (N = 57,576), living in 378 towns of Colombia, during a two years’ follow-up.

Persistence to a prescribed therapy is defined as frequency of repurchase and duration of use greater than 80% throug the entire treatment. Subsequently, a bivariate analysis was performed to identify the association between studied variables and finally their predictive power in persistence to the evaluated therapy after 6, 12 and 17 months, through a binary logistic regression.

Results: The most relevant predictor variables of persistence as an outcome at six, 12 and 17 months were: age (for contraceptives, lipid-lowering agents and phlebotonics), “type of replacement” for antihypertensives, and “type of delivery” for antiresorptives.

Conclusion: Persistence to chronic therapies and contraceptives, has multifactorial etiology in a no - cost drug replacement program; where patient's, drug’s and replacement model variables are involved. Non-persistence to studied drugs was high in all therapeutic groups, which is striking considering that it is a totally free drug replacement program.