We examined trends in hip fracture incidence in Denmark from 1980 to 2014, trends in subsequent 1-year mortality, and the prognostic impact of sex, age, and comorbidity.
This nationwide cohort study prospectively collected data from population-based Danish registries. We included 262,437 patients with incident hip fracture and assessed comorbidity using the Charlson Comorbidity Index (CCI).
Despite slight increases in incidence rates (IRs) of hip fracture up to the mid-1990s, the annual IR decreased by 29% from 1980 to 2014 in women but remained stable in men. Decrease affected all age groups. IR decreased in patients without comorbidity but increased with increasing comorbidity (13% in patients with moderate and 510% in patients with very severe comorbidity). Adjusted mortality rate ratios (MRRs) following hip fracture in 2010–2014 compared with 1980–1984 were 0.68 (95% confidence interval [CI] = 0.65, 0.71) within 30 days and 0.63 (95% CI = 0.61, 0.66) within 31–365 days. The mortality decreased up to 40% irrespective of comorbidity. Compared with patients with no comorbidity, those with very severe comorbidity had adjusted MRRs of 2.48 (95% CI = 2.39, 2.56) and 2.81 (95% CI = 2.74, 2.88) within 30 days and 31–365 days post-hip fracture, respectively.
Although the incidence rate of hip fracture increased substantially with increasing comorbidity, the following 1-year mortality decreased by 40% from 1980 through 2014 irrespective of sex, age, and comorbidity level, suggesting improvement in both treatment and rehabilitation of patients with hip fracture. Comorbidity burden was, however, a strong prognostic factor for 1-year mortality after hip fracture.
aDepartment of Clinical Epidemiology, Aarhus University hospital, Aarhus N, Denmark; bDepartment of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; cClinical Epidemiology Unit, Department of Medicine, Karolinska Institutet, Solna, Sweden; and dCentre for Pharmacoepidemiology, Department of Medicine, Karolinska Institutet, Solna, Sweden.
Submitted 19 July, 2016; accepted 27 July, 2017.
Supported by a grant from Aarhus University Research Foundation and by the Program for Clinical Research Infrastructure (PROCRIN) established by the Lundbeck Foundation and the Novo Nordisk Foundation. These funding sources played no role in the study design, collection, analysis, and interpretation of data, the writing of the article, and the decision to submit the article for publication.
All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declared that (1) no authors have received support from any pharmaceutical company for the submitted work. The Department of Clinical Epidemiology at Aarhus University Hospital, the Centre for Pharmacoepidemiology at the Karolinska Institutet, and the Department of Global Public Health and Primary Care, University of Bergen are involved, however, in studies with funding from various pharmaceutical companies as research grants to (and administered by) these academic institutions. None of these studies have any direct relation to the present study; (2) A.B.P., V.E., S.S., Y.T.L., A.W., A.L., G.S.T., and H.T.S. have no personal financial relationships with any company that might have an interest in the submitted work in the previous 3 years; (3) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and (4) no authors have nonfinancial interests that may be related to the submitted work.
Statement on availability of data: Due to Danish legislation, the data are not publicly available. However, the corresponding author would be happy to answer any question about data.
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Correspondence: Alma B. Pedersen, Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43–45, 8200 Aarhus N, Denmark. E-mail: firstname.lastname@example.org.