Hip fractures in the winter - Using the National Hip Fracture Database to examine seasonal variation in incidence and mortality.

We set out to examine the implications of seasonal variation in hip fracture for trauma services and for the frail older people who typically suffer this injury. Since 2007 the National Hip Fracture Database (NHFD) has been reporting data for all over-60 year old patients presenting in England, Wales and Northern Ireland. We analysed published NHFD data for the 450,764 people who presented during the seven years from April 2011 to March 2018. We found marked seasonal variation in the number of people presenting: 8% more people presenting in the winter months (December-February) than in the summer (June-August). The total number of people dying within 30 days of hip fracture was 30.5% higher among those presenting in these winter months. In total 33,649 people (7.5%) died within 30 days of hip fracture, but this figure varied significantly (p < 0.001, Chi2 test); ranging from 6.7% in July to 8.7% (30% higher) in January. The public health impact of these findings is significant. An 8% increase in hip fracture numbers during the winter would equate with 1250 additional fractures during these months each year. Patients average over 20 days in hospital, so these additional cases will compound the stresses on hospital services over the Christmas and New Year holiday period. Such factors must be taken into consideration when organising trauma services if we are to try and avoid the additional 325 deaths that we found to occur each winter.