Secular trend in the incidence of hip fracture in Catalonia, Spain, 2003–2014

Objectives: to describe the secular trend and seasonal variation in the incidence of hip fracture (HF) over 12 years (2003-2014) in Catalonia, the community with the highest incidence of HF in Spain. Methods: data about age, gender, type of fracture and month of hospitalisation among patients aged 65 years and older discharged with a diagnosis of HF were collected. Crude and age-standardised annual incidence rate were reckoned. To analyse HF trend, the age/sex-adjusted average annual change in incidence (incidence rate ratio, IRR) was calculated. Results: we identified 100,110 HF in the period, with an increase of 16.9% (women 13.4%; men 28.4%). Trochanteric fractures were the most frequent (55.8%). The crude incidence rate (per 100,000 population) decreased from 677.2 (95% confidence interval (95% CI) 662.0-692.7) to 657.6 (95% CI 644.0-671.5). The standardised incidence rate decreased from 754.0 (95% CI 738.6-769.3) to 641.5 (95% CI 627.7-655.3), with a sharp decrease in women (-16.8%) while it was stable in men. The incidence by type of fracture was stable. The trend throughout the period showed a slight decrease with IRR 0.99 (95% CI 0.98-0.99; P = 0.025). The incidence was stable in the oldest group (+85 years), while there was a downward trend in the younger groups. A significant seasonal pattern was observed, with more cases in winter and less in summer (spring as reference). Conclusions: the secular trend reveals a decreasing incidence of HF although the absolute number has increased in the last 12 years in Catalonia. Trochanteric fractures were the most prevalent and a seasonal pattern was observed, with more cases in winter.