Hip fractures in older adults in Ontario, Canada—monthly variation, insights, and implications

Background — In older adults, hip fractures have been described to peak in cooler months. Seasonal differences in patient vulnerability to fracture and social/behavioural factors might contribute to these trends.

Methods — Using linked health-care databases in Ontario Canada, we examined monthly variation in hip fracture hospitalizations in those > 65 years (2011–2015). We stratified results by age category (66-79, ≥80 years). We then examined for variation in the demographic and comorbidity profiles of patients across the months, and as an index of contributing social/behavioural factors, noted variation in health-care behaviours.

Results — There were 47,971 and 52,088 hospitalizations for hip fracture in those 66–79, and ≥80 years, respectively. There was strong seasonality in fractures in both groups. Peaks occurred in October and December when patients appeared most vulnerable. Rates fell in the summer in those 66-79 years, and in the late winter in those ≥80 years (when health-care utilization also declined). A smaller peak in fractures occurred in May in both groups.

Conclusions — Hip fractures peak in the autumn, early winter, and spring in Canada. A dip in fractures occurs in the late winter in the oldest old. Environmental factors might play a role, but seasonal vulnerability to fracture and winter isolation might also be influential.