title: Polypharmacy of medications and fall-related fractures in older people in Japan: a comparison between driving-prohibited and driving-cautioned medications.
abstract: OBJECTIVE
  Polypharmacy is a risk factor for fall-related fractures. However, it is unclear whether polypharmacy itself is a direct risk factor. The aim of this study was to assess the association between the risk of fall-related fractures and polypharmacy of driving-prohibited and driving-cautioned medications in older outpatients.
  
  
  METHODS
  We conducted a cross-sectional study of outpatients aged ≥65 years receiving any medication, using two sampling data sets from the October 2011 and October 2012 national insurance claims in Japan. Using logistic regression models, we analysed the association between the numbers of driving-prohibited or driving-cautioned medications administered or dispensed to patients and the occurrence of fall-related fractures.
  
  
  CONCLUSIONS
  In both analysis populations (n = 303 311 and n = 326 219), the adjusted odds ratio of driving-prohibited medications for the occurrence of fall-related fractures significantly increased as the number of these medications per patient increased (95% confidence interval: 0, 1-2, 3-4, 5-6, 7-8 and ≥9 medications; reference, 0·95-1·24, 1·18-1·79, 1·47-2·96, 1·26-5·21 and 1·50-15·2 in October 2011 and reference, 1·11-1·42, 1·39-2·03, 1·33-2·72, 1·53-5·49 and 1·30-13·0 in October 2012). The association was maintained even for sensitivity analyses restricted to medications administered orally or orally and by injection. However, a similar association was not observed for driving-cautioned medications.
  
  
  CONCLUSIONS
  Medication class is a more important risk factor for fall-related fractures rather than polypharmacy alone with no regard to medication class.
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-City, Kagawa, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Iihara
authors.affiliation: Faculty of Health and Welfare, Tokushima Bunri University, Sanuki-City, Kagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Bando
authors.affiliation: Ayagawa National Health Insurance Sue Hospital, Ayauta-gun, Kagawa, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohara
authors.affiliation: Faculty of Health and Welfare, Tokushima Bunri University, Sanuki-City, Kagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-City, Kagawa, Japan.|Department of Pharmacy, Sanuki City Hospital, Sanuki-City, Kagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nishio
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-City, Kagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Okada
authors.affiliation: Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-City, Kagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kirino
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D001334:Automobile Driving; D003430:Cross-Sectional Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D010045:Outpatients; D019338:Polypharmacy; D012307:Risk Factors
keywords: accidental falls; aged; drug-related side effects and adverse reactions; fractures; polypharmacy