Reference number: OPUSeJ201201262030MPR
Title: Revisiting the Medication Possession Ratio Threshold for Adherence in Lipid Management
Author(s): Jonathan H. Watanabe, Mark Bounthavong, and Timothy Chen.
Abstract: Objective: We sought to evaluate the relationship between different levels of medication possession ratio (MPR) attained and achievement of clinically meaningful reductions in lipid levels.
Research design and methods: Retrospective cohort study of 4 691 new statin users from the Department of Veteran Affairs (VA). Subjects were required to be eligible for VA medical and pharmacy services throughout 1 year study period from index date and to have complete data for exposure, outcome, and adjustment variables. MPR was defined as days supplied of prescription medication divided by days of observation.
Main outcome measures: Achieving 25% or greater reduction from baseline in lipid for 3 lipid outcomes: non-high-density lipoprotein (non-HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and total cholesterol (TC).
Results: We observed a statistically significant trend of increasing proportion of study subjects achieving a 25% reduction or more for all 3 lipid outcomes (P-values < .001 for each of the 3 outcomes using the Cochran-Armitage Trend Test).
Via multiple logistic regression, odds ratios (ORs) for each of the 3 outcomes were at a maximum for the 0.9 to 1.0 MPR category with ORs of 12.07 (95% Confidence Interval (CI), 9.03, 16.13) for the non-HDL cholesterol outcome; 11.04 (95% CI, 8.53, 14.55) for the LDL cholesterol outcome; and 8.84 (95% CI, 6.45, 12.12) for the TC outcome. Direct comparison of the 0.9 to 1.0 MPR category versus the 0.8 to 0.89 MPR category demonstrated increased in odds of achieving 25% or more reduction for all 3 lipid outcomes.
Conclusions: We conclude that significant improvements in outcomes are achieved with higher MPR thresholds than commonly targeted. The authors propose consideration of an MPR-adherence threshold of 0.9 MPR. Limitations include the possible modification of study findings in non-VA settings. MPR is a secondary adherence measure based on refill frequency
Author bio: N/A
Sponsor editor: N/A
Keywords: Adherence; Medication Possession Ratio; Lipids; Outcomes
Subject: Medicine/ lipids
Bibliography: (alphabetical) N/A
Citation: Watanabe, Jonathan H., Mark Bounthavong, and Timothy Chen. “Revisiting the Medication Possession Ratio Threshold for Adherence in Lipid Management.” Current Medical Research & Opinion (2013): 1-31. Posted online on January 15, 2013. (doi:10.1185/03007995.2013.766164) http://informahealthcare.com/doi/abs/10.1185/03007995.2013.766164