title: Clinically important drug-disease interactions and their prevalence in older adults.
abstract: BACKGROUND
  Older adults may have decreased homeostatic reserve, have multiple chronic diseases, and take multiple medications. Therefore, they are at risk for adverse outcomes after receiving a drug that exacerbates a chronic disease.
  
  
  OBJECTIVE
  The aims of this study were to compile a list of clinically important drug-disease interactions in older adults, obtain the consensus of a multidisciplinary panel of geriatric health care professionals on these interactions, and determine the prevalence of these interactions in a sample of outpatients.
  
  
  METHODS
  This analysis included a 2-round modified Delphi survey and cross-sectional study. Possible drug-disease interactions in patients aged > or =65 years were identified through a search of the English-language literature indexed on MEDLINE and International Pharmaceutical Abstracts (1966-July 2004) using terms that included drug-disease interaction, medication errors, and inappropriate prescribing. Nine health care professionals with expertise in geriatrics (2 geriatricians, 7 geriatric clinical pharmacist specialists) were selected based on specialty training and continuing clinical work in geriatrics, academic appointments, and geographic location. The panel rated the importance of the potential drug-disease interactions using a 5-point Likert scale (from 1 = definitely not serious to 5 = definitely serious). Consensus on a drug-disease interaction was defined as a lower bound of the 95% CI > or =4.0. The prevalence of drug-disease interactions was determined by applying the consensus criteria to a convenience sample of frail older veterans at hospital discharge who were enrolled in a health services intervention trial.
  
  
  RESULTS
  The panel reached consensus on 28 individual drug-disease interactions involving 14 diseases or conditions. Overall, 205 (15.3%) of the 1340 veterans in the sample had > or =1 drug-disease interaction. The 2 most common drug-disease interactions were use of first-generation calcium channel blockers in patients with congestive heart failure and use of aspirin in patients with peptic ulcer disease (both, 3.7%).
  
  
  CONCLUSIONS
  A survey of multidisciplinary geriatric health care professionals resulted in a concise consensus list of clinically important drug-disease interactions in older adults. Further research is needed to examine the impact of these drug-disease interactions on health outcomes and their applicability as national measures for the prevention of drug-related problems.
authors.affiliation: Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Minneapolis, Minnesota, USA. Electronic address: lindb047@umn.edu.
authors.forename: Catherine I
authors.initials: CI
authors.lastname: Lindblad
authors.affiliation: Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Center for Health Equity Research and Promotion, Geriatric Research, Education, and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh Pennsylvania, USA; Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh Pittsburgh, Pennsylvania, USA.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Hanlon
authors.affiliation: Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Cynthia R
authors.initials: CR
authors.lastname: Gross
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Sloane
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, USA; Department of Biostatistics and Bioin formatics, Duke University Medical Center, Durham, North Carolina, USA.
authors.forename: Carl F
authors.initials: CF
authors.lastname: Pieper
authors.affiliation: Philadelphia College of Pharmacy, University of the Sciences in Philadelphia, Philadelphia, Pennsylvania, USA.
authors.forename: Emily R
authors.initials: ER
authors.lastname: Hajjar
authors.affiliation: Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Pharmacy and Therapeutics, School of Pharmacy, University of Pittsburgh Pittsburgh, Pennsylvania, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Ruby
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, USA; Division of Geriatric Medicine, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Durham, North Carolina, USA.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Schmader
authors.lastname: Multidisciplinary Consensus Panel
mesh_terms: D000368:Aged; D001241:Aspirin / Q000009:adverse effects; D002121:Calcium Channel Blockers / Q000009:adverse effects; D002908:Chronic Disease; D064420:Drug-Related Side Effects and Adverse Reactions; D016330:Frail Elderly; D015577:Geriatric Assessment; D006801:Humans; D008508:Medication Errors / Q000706:statistics & numerical data*; D015995:Prevalence; D014728:Veterans
chemical_list: D002121:Calcium Channel Blockers; D001241:Aspirin