title: Type, number or both? A population-based matched case-control study on the risk of fall injuries among older people and number of medications beyond fall-inducing drugs.
abstract: OBJECTIVE
  Drug use is a modifiable risk factor for fall-related injuries in older people. Whereas the injurious effect of polypharmacy is established, that of low numbers of medications has not been fully ascertained. Neither do we know whether it is the number per se or the type of medications that actually matters. We assessed this question for fall injuries leading to hospitalization.
  
  
  METHODS
  National register-based, population-based, matched case-control study.
  
  
  METHODS
  Community dwellers aged 65+ years living in Sweden between March 2006 and December 2009.
  
  
  METHODS
  Cases (n = 64,399) were identified in the national inpatient register and four controls per case were randomly matched by gender, date of birth and residential area. The association between number of prescribed medications, assessed through linkage with the Swedish prescribed drug register, and the risk of injurious falls was estimated with odds ratios with 95% confidence intervals using conditional logistic regression, adjusted for demographic and health status.
  
  
  RESULTS
  The number of medications was associated with an increased risk of fall injury in a dose-response fashion, even after adjustment for marital status, comorbidity and number of fall-risk-inducing drugs (FRIDs). Using ten or more medications was associated with an almost two-fold higher risk (adjusted OR: 1.76, 95% CI: 1.66 to 1.88). When stratified by use (or not) of at least one FRID, the association weakened slightly among both non-users (adjusted OR: 1.50, 95% CI: 1.34 to 1.67) and users (adjusted OR: 1.67, 95% CI: 1.58 to 1.77).
  
  
  CONCLUSIONS
  In older people, not only large but also small numbers of medications may affect the risk for them to sustain injurious falls. Although the mechanisms lying behind this are complex, the finding challenges the prevention strategies targeting either specific types of medications (FRIDs) or high numbers of them.
authors: Karolinska Institutet, Department of Public Health Sciences, Stockholm, Sweden.
authors: Lucie
authors: L
authors: Laflamme
authors: Karolinska Institutet, Department of Public Health Sciences, Stockholm, Sweden.
authors: Joel
authors: J
authors: Monárrez-Espino
authors: Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors: Kristina
authors: K
authors: Johnell
authors: Karolinska Institutet, Department of Public Health Sciences, Stockholm, Sweden.
authors: Berty
authors: B
authors: Elling
authors: Karolinska Institutet, Department of Public Health Sciences, Stockholm, Sweden.
authors: Jette
authors: J
authors: Möller
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000369:Aged, 80 and over; D004358:Drug Therapy / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D057187:Independent Living / Q000706:statistics & numerical data; D008297:Male; D055553:Prescription Drugs / Q000008:administration & dosage / Q000009:adverse effects; D014947:Wounds and Injuries / Q000453:epidemiology* / Q000209:etiology
chemical_list: D055553:Prescription Drugs