title: Use of a frailty index to identify potentially inappropriate prescribing and adverse drug reaction risks in older patients.
abstract: BACKGROUND
  potentially inappropriate prescribing (PIP) is a significant problem in health care today. We hypothesise that if doctors were given a single indicator of PIP and adverse drug reaction (ADR) risk on a patient's prescription, it might stimulate them to review the medicines. We suggest that a frailty index (FI) score may be such a suitable indicator.
  
  
  OBJECTIVE
  to determine whether a positive relationship exists between a patient's frailty status, the appropriateness of their medications and their propensity to develop ADRs. Compare this to just using the number of medications a patient takes as an indicator of PIP/ADR risk.
  
  
  METHODS
  a frailty index was constructed and applied to a patient database. The associations between a patient's FI score, the number of instances of PIP on their prescription and their likelihood of developing an ADR were determined using Pearson correlation tests and χ(2) tests.
  
  
  RESULTS
  significant correlation between FI score instances of PIP was shown (R = 0.92). The mean FI score above which patients experienced at least one instance of PIP was 0.16. Patients above this threshold were twice as likely to experience PIP (OR = 2.6, P < 0.0001) and twice as likely to develop an ADR (OR = 2.1, P < 0.0001). Patients taking more than six medications were 3 times more likely to experience PIP.
  
  
  CONCLUSIONS
  an FI score is a potentially relevant clinical indicator for doctors to critically assess a patient's prescription for the presence of PIP and ultimately prevent ADRs, especially when used in tandem with the number of medications a patient takes.
authors.affiliation: School of Pharmacy, Cavanagh Pharmacy Building College Road Cork, University College Cork, Cork, Ireland.
authors.forename: Shane
authors.initials: S
authors.lastname: Cullinan
authors.affiliation: Department of Geriatric Medicine, Cork University Hospital, Cork, Ireland.
authors.forename: Denis
authors.initials: D
authors.lastname: O'Mahony
authors.affiliation: School of Pharmacy, Cavanagh Pharmacy Building College Road Cork, University College Cork, Cork, Ireland.
authors.forename: David
authors.initials: D
authors.lastname: O'Sullivan
authors.affiliation: School of Pharmacy, Cavanagh Pharmacy Building College Road Cork, University College Cork, Cork, Ireland.
authors.forename: Stephen
authors.initials: S
authors.lastname: Byrne
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D016009:Chi-Square Distribution; D015897:Comorbidity; D016208:Databases, Factual; D064420:Drug-Related Side Effects and Adverse Reactions / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D057970:Inappropriate Prescribing / Q000009:adverse effects*; D008297:Male; D016017:Odds Ratio; D019338:Polypharmacy; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012307:Risk Factors
keywords: adverse drug reactions; frailty; inappropriate prescribing; older people