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Generic substitution does not seem to affect adherence negatively in elderly polypharmacy patients[Note *. * Only oral prescription drugs taken throughout the study ...]
Author(s) -
Olesen Charlotte,
Harbig Philipp,
Barat Ishay,
Damsgaard Else Marie
Publication year - 2013
Publication title -
pharmacoepidemiology and drug safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.023
H-Index - 96
eISSN - 1099-1557
pISSN - 1053-8569
DOI - 10.1002/pds.3497
Subject(s) - medicine , polypharmacy , medical prescription , pharmacoepidemiology , confidence interval , odds ratio , affect (linguistics) , pill , drug , generic drug , pediatrics , pharmacology , linguistics , philosophy
ABSTRACT Purpose To investigate the association between generic substitutions and medication adherence in elderly patients with prescribed polypharmacy. Methods Our study included 672 patients aged 65+ years, living at home in the municipality of Aarhus (Denmark), who at the time of enrolment took at least five prescription drugs daily including both short‐term and long‐term treatment independently of kind of administration route but without assistance. In this paper, only oral drugs for long‐term treatment are included in the analysis resulting in median of three drugs per patient. Adherence was assessed by pill counts. Patients with a mean adherence rate <80% across all oral drugs consumed for long‐term treatment were categorised as non‐adherent. The number of generic substitutions during 1 year was retrieved from the National Health Insurance prescription database. Each change in either a drug's or a manufacturer's name was regarded as a substitution. The association between generic substitution and the mean adherence rate to all drugs was analysed by contingency table analyses and a trend test. Results During 1 year, at least one substitution was experienced by 83.6% of patients ( n = 562). Patients non‐adherent to long‐term oral treatment ( n = 46) amounted to 8% of all patients who experienced substitutions. Amongst 110 elderly patients (16.4%) who did not experience substitutions, 16% were non‐adherent (odds ratio 0.46; 95% confidence interval 0.25–0.82). Conclusion As generic substitution in elderly patients undergoing polypharmacy appears not to affect adherence to long‐term drug treatment negatively, there seems to be no obvious reason for avoiding generic substitution in such patients. Copyright © 2013 John Wiley & Sons, Ltd.