Ambulatory antibiotic use and prescription drug coverage in older adults.

TitleAmbulatory antibiotic use and prescription drug coverage in older adults.
Publication TypeJournal Article
Year of Publication2010
AuthorsZhang Y, Lee BY, Donohue JM
JournalArch Intern Med
Volume170
Issue15
Pagination1308-14
Date Published2010 Aug 9
ISSN1538-3679
KeywordsAdministration, Oral, Aged, Aged, 80 and over, Ambulatory Care, Anti-Bacterial Agents, Cohort Studies, Drug Costs, Drug Prescriptions, Female, Humans, Insurance Coverage, Logistic Models, Macrolides, Male, Medicare, Medicare Part D, Odds Ratio, Physician's Practice Patterns, Quinolones, Research Design, Respiratory Tract Infections, United States
Abstract

BACKGROUND: Several studies have shown that use of medications to treat chronic conditions is highly sensitive to out-of-pocket price and influenced by changes in insurance coverage. Because antibiotics target infections and are used for a short period, one may expect antibiotic use to be less responsive to price. However, no studies have evaluated how antibiotic use changes with drug coverage. We evaluate changes in ambulatory oral antibiotic use after implementation of the Medicare drug benefit (Part D).METHODS: We conducted a comparison group analysis 2 years before and after implementation of Part D using insurance claims data from a large Medicare Advantage plan (January 1, 2004, through December 31, 2007). Outcomes included the likelihood of using any oral antibiotics and major antibiotic subclasses among 35 102 older adults and rates of antibiotic use among those with pneumonia and other acute respiratory tract infections.RESULTS: Overall antibiotic use increased most among those who did not previously have drug coverage (relative odds ratio [OR], 1.58; 95% confidence interval [CI], 1.36-1.85). Use of the broad spectrum antibiotic subclasses of quinolones (OR, 1.70; 95% CI, 1.35-2.15) and macrolides (1.59; 1.26-2.01) increased more than the use of other subclasses, especially for those with prior drug coverage. Rates of ambulatory antibiotic use associated with pneumonia increased (OR, 3.60; 95% CI, 2.35-5.53) more than those associated with other acute respiratory tract infections (2.29; 1.85-2.83).CONCLUSIONS: Antibiotic use increased among older adults whose drug coverage improved after Part D implementation, with the largest increases for broad spectrum, newer, and more expensive antibiotics. Our study suggests reimbursement may play a role in addressing inappropriate antibiotic use.

DOI10.1001/archinternmed.2010.235
Alternate JournalArch. Intern. Med.
PubMed ID20696953
PubMed Central IDPMC3784024
Grant List1R01HS017695 / HS / AHRQ HHS / United States
1R01HS018657-01 / HS / AHRQ HHS / United States
1R34 MH082682 / MH / NIMH NIH HHS / United States
1RC1MH088510-01 / MH / NIMH NIH HHS / United States
1U54GM088491-0109 / GM / NIGMS NIH HHS / United States
U54 GM088491 / GM / NIGMS NIH HHS / United States
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