Medication Adherence using Medication Possession Ratio and Proportion of Days Covered among Elderly Diabetic Patients Visiting a Tertiary Care Hospital in Puducherry

Abstract

Background: Patient adherence to treatment is crucial for successful therapy while treating chronic conditions like diabetes mellitus. Medication possession ratio (MPR) and proportion of Days Covered (PDC) are the most common measures of medication adherence using refill records. Methods: A prospective hospital-based longitudinal study was carried out among elderly patients, both males and females on oral hypoglycaemic medication from May-August 2019 in the Department of General Medicine in Puducherry. MPR was calculated as the sum of the days' supply for all fills of a given drug in a particular period divided by the number of days in the period while PDC was calculated as the number of days the drug supplied during the study period divided by the number of days in the study period. MPR and PDC ≥ 80% was considered as adherence to medication. Results: In our study, 80% of elderly diabetic patients were adherent to medication according to medication possession ratio (MPR), while adherence according to the proportion of days covered was much lesser and was only 64.4%. We found a significant association between medication adherence in elderly diabetic patient’s factors such as monthly family income, literacy, and presence of a caretaker while there was no association between medication adherence in elderly diabetic patients upon the age of the patient, number of drugs prescribed and monthly cost of the medicines. Conclusion: Medication adherence in elderly diabetic patients mainly depends on many factors such as monthly family income, literacy and presence of the caretaker and not depending upon the age of the patient, number of drugs prescribed and monthly cost of the medicines. Larger studies are necessary to realize the proper impact of nonadherence on this group of the population