Suboptimal prescribing in elderly outpatients: Potentially harmful drug-drug and drug-disease combinations

Chunliu Zhan, Rosaly Correa-De-Araujo, Arlene S. Bierman, Judy Sangl, Marlene R. Miller, Stephen W. Wickizer, Daniel Stryer

Research output: Contribution to journalArticlepeer-review

80 Scopus citations


OBJECTIVES: To assess the prevalence and correlates of potentially harmful drug-drug combinations and drug-disease combinations prescribed for elderly patients at outpatient settings. DESIGN: Retrospective analysis of the 1995-2000 National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS). SETTING: Physician offices and hospital outpatient departments. PARTICIPANTS: Outpatient visits by patients aged 65 and older in the NAMCS and NHAMCS (n = 70,203). MEASUREMENTS: Incidences of six drug-drug combinations and 50 drug-disease combinations that can place elderly patients at risk for adverse events according to expert consensus panels. RESULTS: Overall, 0.74% (95% confidence interval (CI) = 0.65-0.83) of visits with two or more prescriptions had at least one inappropriate drug-drug combination, and 2.58% (95% CI = 2.44-2.72) of visits with at least one prescription had one or more inappropriate drug-disease combinations. Of visits with a prescription of warfarin, 6.60% (95% CI = 5.46-7.74) were prescribed a drug with potentially harmful interaction. Of patients with benign prostatic hypertrophy, 4.06% (95% CI = 3.06-5.06) had at least one of six drugs that should be avoided. The number of drugs prescribed is most predictive of inappropriate drug-drug and drug-disease combinations. CONCLUSION: Potentially harmful drug-drug and drug-disease combinations occur in various degrees in outpatient care in the elderly population. Targeting combinations such as those involving warfarin that are high in prevalence and potential harm offers a practical approach to improving prescribing and patient safety.

Original languageEnglish (US)
Pages (from-to)262-267
Number of pages6
JournalJournal of the American Geriatrics Society
Issue number2
StatePublished - Feb 2005


  • Aged
  • Drug interactions
  • Medication errors
  • Prescription drugs

ASJC Scopus subject areas

  • Geriatrics and Gerontology


Dive into the research topics of 'Suboptimal prescribing in elderly outpatients: Potentially harmful drug-drug and drug-disease combinations'. Together they form a unique fingerprint.

Cite this