Trends in benzodiazepine prescribing under Medicare Part D in USA: Outpatient settings 2005-2009

Abstract

Objectives: The objective of the study was to examine the trend of benzodiazepine prescribing under Medicare Part D formulary restriction. Methods: A secondary data analysis was conducted using the National Ambulatory Medical Care Survey between 2005 and 2009. Subjects were identified from ambulatory physician office visits where the primary payment source was Medicare and at least one US Food and Drug Administration (FDA)-approved benzodiazepine was prescribed. Data trend were graphically plotted and further analysed using segmented regression. Key findings: An estimated 4.9 billion visits to office-based physicians from 2005 to 2009 of which 1.2 billion (24.24%) were made by Medicare recipients. Of these, 86.9 million (7.38%) visits received at least one FDA-approved benzodiazepine including alprazolam (33.3%), lorazepam (24.4%), clonazepam (16.2%), diazepam (12.1%), etc. One year after the passage of Medicare Part D benzodiazepine exclusion, benzodiazepine prescribing decreased 1.83%. However, it had dramatically increased (21.7%) in 2007. Results from segmented regression indicated that implementation of Medicare Part D drug benefits, with benzodiazepine exclusion, is significantly associated with benzodiazepine utilisation (P=0.015). Conclusion: The study findings indicated that benzodiazepine prescribing was not decreased by Medicare Part D formulary exclusion. Several factors could explain this phenomenon: (1) economic perspectives, (2) Medicare supplement programmes, (3) physician prescribing patterns/habits, (4) elderly dependence on benzodiazepines. Despite benzodiazepines having been allowed on Medicare Part D formularies in 2013, this amendment may lead to an even greater importance to healthcare professionals and policy makers by providing comprehensive patient care that ensures optional medication therapy outcomes.