Geographic variation in hip fracture surgery rate, care quality and outcomes: a comparison between national registries in Ireland and Denmark

Summary: Ireland and Denmark have similar hip fracture surgery rates but differences in care quality indicators and patterns of intracapsular fracture repair. Very high variation in total hip arthroplasty rate within both countries and higher observed early mortality in Denmark require further investigation. Purpose: To explore and compare geographic variation of hip fracture surgery rate, care quality and outcomes in Ireland and Denmark. Methods: Patients aged ≥ 65 years with surgically treated hip fracture were included from the Irish Hip Fracture Database (years = 2017–2020, n = 12,904) and the Danish Multidisciplinary Hip Fracture Registry (years = 2016–2017, n = 12,924). The age and sex standardised rate of hip fracture surgery and the proportion of patients with seven process quality indicators, three surgery types and four outcomes were calculated. Systematic components of variation (SCV) were calculated based on hospital area (6 Irish hospital groups, 5 Danish regions). Results: The age and sex standardised rate of hip fracture surgery per 1000 older population in 2017 was 4.7 (95% CI = 4.4–5.1) in Ireland and 5.3 (95% CI = 5.1–5.5) in Denmark. Ireland had lower rates of surgery within 36 h (59% versus 84%), nutritional assessment (27% versus 84%) and pre-discharge mobility recording (52% versus 92%). Patterns of intracapsular fracture repair also differed between countries (hemiarthroplasty: Ireland = 85%, Denmark = 52%). Both countries had very high variation for total hip arthroplasty (THA) provision (SCV Ireland = 10.6, Denmark = 97.9). Ireland had longer hospital stays (median 12 versus 7 days), but lower 7-day (1.0% versus 3.1%) and 14-day (2.0% versus 5.5%) mortality. Conclusion: Ireland and Denmark have similar hip fracture surgery rates, but differences in care quality, surgery patterns and outcomes. High variation in THA provision and observed differences in mortality require further exploration. In Ireland, there is scope for improvement regarding early surgery, mobility, nutrition assessment and improved post-discharge follow-up.