title: Dementia diagnosis and osteoporosis treatment propensity: a population-based nested case-control study.
abstract: OBJECTIVE
  Increasing age and a diagnosis of dementia both dramatically increase the risk of serious osteoporosis-related sequela. We sought to examine the factors associated with osteoporosis treatment, in relation to dementia diagnosis, in older adults with osteoporosis.
  
  
  METHODS
  This was a population-based, retrospective, nested, case-control study utilizing administrative healthcare data from British Columbia, Canada. Community-based individuals aged ≥65 years with an osteoporosis diagnosis and continuous enrolment in the provinces' drug plan between 1991 and 2007 were eligible for inclusion. A multivariate logistic regression model was assembled to examine the relationship between dementia diagnosis, age, sex, other comorbidity, residence and osteoporosis medication dispensation.
  
  
  RESULTS
  Almost half of the total osteoporosis cohort (n = 39 452) were dispensed an osteoporosis medication during the study period. Individuals with no dementia diagnosis were dispensed a medication significantly more often than those with a diagnosis of dementia (P < 0.001). Those patients with dementia (n = 13 315), who had been dispensed an osteoporosis drug, were more often younger, female, had not sustained a previous fracture, had ≥ 4 comorbid conditions and lived in the most central health region (P < 0.001). A diagnosis of dementia was found to be a significant negative predictor of osteoporosis drug dispensation (adjusted OR 0.55; 95% CI 0.44-0.69). Increasing comorbidity was significantly associated with receiving treatment (adjusted OR 3.30; 95% CI 2.88-3.78).
  
  
  CONCLUSIONS
  Despite the wide availability of osteoporosis medications, our findings suggest that many older adults with a diagnosis of dementia, but not necessarily fewer comorbid conditions, were not receiving treatment.
authors.affiliation: Faculty of Health Disciplines, Athabasca University, Edmonton, Alberta, Canada; Faculty of Nursing, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Knopp-Sihota
authors.forename: Greta G
authors.initials: GG
authors.lastname: Cummings
authors.forename: Christine V
authors.initials: CV
authors.lastname: Newburn-Cook
authors.forename: Joanne
authors.initials: J
authors.lastname: Homik
authors.forename: Don
authors.initials: D
authors.lastname: Voaklander
mesh_terms: D000367:Age Factors; D000368:Aged; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D001955:British Columbia / Q000453:epidemiology; D015897:Comorbidity; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology; D004164:Diphosphonates / Q000627:therapeutic use*; D018450:Disease Progression; D015914:Estrogen Replacement Therapy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D009483:Neuropsychological Tests; D010024:Osteoporosis / Q000188:drug therapy* / Q000453:epidemiology; D011379:Prognosis; D057216:Propensity Score; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates
keywords: claims data; comorbidity; dementia; older adults; osteoporosis