ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH Dementia diagnosis and osteoporosis treatment propensity: A population-based nested case–control study Jennifer A Knopp-Sihota, 1,2 Greta G Cummings, 2 Christine V Newburn-Cook, 2 Joanne Homik, 3 Don Voaklander 4 1 Faculty of Health Disciplines, Athabasca University, 2 Faculty of Nursing, 3 Department of Medicine, and 4 School of Public Health, University of Alberta, Edmonton, Alberta, Canada Aim: 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). Conclusion: 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. Geriatr Gerontol Int 2014; 14: 121–129. Keywords: claims data, comorbidity, dementia, older adults, osteoporosis. Introduction Aging of the population has led to a shift in disease profiles with age-related chronic conditions, such as osteoporosis, becoming important public health con- cerns. Osteoporosis is a skeletal disease characterized by low bone mass and micro-architecture deterioration of bone, leading to increased bone fragility and the risk of fracture. 1 Fragility fractures, the most serious osteoporosis-related disease burden, are associated with not only high healthcare-related expenditures, but also increased mortality and significant post-fracture disability. 2–4 Increasing age, a prior history of fragility fracture and a diagnosis of dementia all dramatically increase the risk of subsequent fracture. 5 Dementia is an umbrella term for a variety of disorders defined by impaired or loss of cognitive function. The incidence of dementia increases exponentially with age; by age 85 years, 33% (men) to 46% (women) of the Canadian population will have been diagnosed with dementia. 6 Dementia has been associated with an increased risk for falls of which hip and other fragility fractures are a common sequela. 7–11 Other common risk factors found in both diseases include nutritional deficiencies, lower sunlight exposure resulting in vitamin D deficiencies, less physical activity and lower body mass indexes. 12 Despite the availability of effective treatments (usually a bisphosphonate drug), 13 there remains an overall low rate of osteoporosis treatment, particularly in older, frailer adults. 14–16 In addition, the frequency with which community-dwelling older adults with dementia are treated with osteoporosis medications has not been well Accepted for publication 26 February 2013. Correspondence: Dr Jennifer Knopp-Sihota NP PhD, Faculty of Health Disciplines, Athabasca University, 1 University Drive, Athabasca, AB, Canada. Email: jknopp@athabascau.ca Geriatr Gerontol Int 2014; 14: 121–129 © 2013 Japan Geriatrics Society doi: 10.1111/ggi.12069 | 121