Nordic hip fracture registries: comparisons toward a minimal common and standardized Nordic Hip Fracture Dataset...

National hip fracture registries in Denmark, Norway, and Sweden collect extensive pre- and post-fracture data. Inspired by the Global Fragility Fracture Network (Global FFN) minimum common dataset, which is not specifically tailored to Nordic healthcare systems, we aimed to evaluate the feasibility of developing a standardized Nordic Hip Fracture Dataset (Nordic-HFD).

We compared 4 Nordic hip fracture registries: the Danish Multidisciplinary Hip Fracture Registry, the Norwegian Hip Fracture Register, the Swedish Fracture Register, and the Swedish Hip Fracture Register (RIKSHÖFT). Variables available in at least 3 registries, including those obtainable through linkage with national health registries, were assessed for definitions and grouped into demographic, surgical, postoperative, complications, and PROM domains.

Across registries, 38 variables were identified. The number of variables available in all 4 registries was 11, while 31 were available in at least 3 registries. After quality review, 30 variables were ultimately considered suitable for inclusion in the proposed Nordic-HFD. Demographic variables such as age, sex, fracture type, pathological fracture, laterality, ASA score, surgical variables such as surgical method, date of surgery, time to surgery, and mortality were directly comparable. Variables on mobility, cognitive impairment, complications, and PROMs may require further harmonization.

Establishing a Nordic-HFD is feasible using existing national registries' infrastructures. The remaining challenge is harmonizing variable definitions to specific research questions and future validation studies. A Nordic-HFD would enhance robust cross-country benchmarking and support international initiatives such as the Global FFN.