title: Prevalence of potentially preventable unplanned hospitalizations caused by therapeutic failures and adverse drug withdrawal events among older veterans.
abstract: Background. Studies of drug-related hospitalizations have focused on adverse drug reactions, but few data are available on therapeutic failures (TFs) and adverse drug withdrawal events (ADWEs) leading to hospitalization among community-dwelling older adults. Thus, we sought to describe the prevalence of unplanned hospitalizations caused by TFs and ADWEs. In addition, we evaluated factors associated with these events in a nationally representative sample of older Veterans.  Methods. This study included 678 randomly selected unplanned hospitalizations of older (age ≥ 65 years) Veterans between December 1, 2003, and November 9, 2006. The main outcomes were hospitalizations caused by a TF and/or an ADWE as determined by a pair of health professionals from review of medication charts and application of the Therapeutic Failure Questionnaire and/or Naranjo ADWE algorithm, respectively. Preventability (ie, medication error) of the admission was also assessed.  Results. Thirty-four TFs and eight ADWEs involving 54 drugs were associated with 40 (5.9%) Veterans' hospitalizations; of these admissions, 90.0% (36/40) were rated as potentially preventable mostly due to medication nonadherence and suboptimal prescribing. The most common TFs that occurred were heart failure exacerbations (n = 8), coronary heart disease symptoms (n = 6), tachyarrhythmias (n = 3), and chronic obstructive pulmonary disease exacerbations (n = 3). Half (4/8) of the ADWEs that occurred were cardiovascular in nature. Multivariable logistic regression modeling indicated that black Veterans (adjusted odds ratio 2.92, 95% CI 1.25-6.80) were significantly more likely to experience a TF-related admission compared with white Veterans.  Conclusions. TF-related unplanned hospitalizations occur more frequently than ADWE-related admissions among older Veterans. Almost all TFs and/or ADWEs are potentially preventable.
authors.affiliation: Department of Medicine (Geriatrics), School of Medicine, University of Pittsburgh,, 3471 Fifth Avenue, Pittsburgh, PA 15213, USA. zam12@pitt.edu
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Marcum
authors.forename: Mary Jo V
authors.initials: MJ
authors.lastname: Pugh
authors.forename: Megan E
authors.initials: ME
authors.lastname: Amuan
authors.forename: Sherrie L
authors.initials: SL
authors.lastname: Aspinall
authors.forename: Steven M
authors.initials: SM
authors.lastname: Handler
authors.forename: Christine M
authors.initials: CM
authors.lastname: Ruby
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Hanlon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003327:Coronary Disease / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006304:Health Status; D006333:Heart Failure; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D019338:Polypharmacy; D029424:Pulmonary Disease, Chronic Obstructive; D013375:Substance Withdrawal Syndrome / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D017211:Treatment Failure; D014728:Veterans