Epidemiology of forearm fractures in adults in Denmark: national age- and gender-specific incidence rates, ratio of forearm to hip fractures, and extent of surgical fracture repair in inpatients and outpatients

National epidemiological studies of forearm fractures are scarce. We examined in- and outpatient rates in Denmark, including anatomical location, surgery, hospitalization ratio, recurrent fractures, and ratio of forearm to hip fractures. This may be useful for triangulation in countries with less detailed information. Rates were higher than previously estimated. Despite a significant contribution to the overall burden of osteoporotic, nonvertebral fractures, relatively little information is available about age- and gender-specific incidence rates for many countries including Denmark. We used national individual patient data on inpatient and outpatient treatment to calculate rates of forearm fractures, taking readmissions into account, with subtables for distal and proximal fractures. We also calculated ratios of forearm to hip fractures that may be useful when imputing forearm fracture rates from other administrative sources. In addition, we report the rates of hospital admission and the rates of surgical treatment, allowing readers to extrapolate from the number of admissions or surgical procedures to incidence rates, should their data sources be less comprehensive. Forearm fracture rates were 278 per 100,000 patient years in men aged 50+ and 1,110 per 100,000 in women aged 50+. The female to male incidence rate ratio was 4.0 for the age group 50+ but close to unity in persons aged 40 or under. Two thirds of patients were treated on an outpatient basis with little difference across age and gender strata. Four out of five fractures were treated conservatively. The rate of forearm fractures in Denmark was somewhat higher in both genders than recently imputed from hip fracture rates and were close to the rates previously reported in studies from Norway and Sweden. The rates of forearm fracture in Denmark are higher than previously estimated and very similar to the high risk reported from studies in Norway and Sweden.