Variation in the incidence of distal radius fractures in the U.S. elderly as related to slippery weather conditions

Abstract

Background: Distal radius fractures are costly and debilitating injuries, especially for the elderly. These fractures often occur from falls and commonly occur outdoors. Inclement weather may increase the risk of fall-related injuries. Small studies have reported an increased risk of distal radius fracture caused by inclement winter weather; larger studies are lacking.

Methods: The authors analyzed a sample of 2007 Medicare claims for distal radius fracture. Weather data were collected for the date and location of each distal radius fracture in the authors' analysis cohort. A novel slipperiness score was used as a measure of the severity of slippery outdoor conditions. Negative binomial regression models evaluated the correlation between slipperiness and distal radius fracture occurrence.

Results: Risk of distal radius fracture was higher in winter months (incidence rate ratio, 1.2; p < 0.001). Days with average temperature less than or equal to 32°F (incidence rate ratio, 1.36; p < 0.001), snow/ice on the ground at the start of the day (incidence rate ratio, 1.45; p < 0.001), and freezing rain (incidence rate ratio, 1.24; p = 0.025) all had an increased risk of distal radius fracture. The risk of sustaining a distal radius fracture was increased 21 percent on days with a slipperiness score above 4 (incidence rate ratio, 1.21; p = 0.007). For each increase in slipperiness score above 4, the incidence rate ratio of distal radius fracture increased as well.

Conclusions: Weather events that create slippery walking conditions, often in the winter, result in an increased risk of distal radius fracture in the elderly. This finding can be used to support resource allocation and awareness and prevention campaigns.

Clinical question/level of evidence: Risk, IV.

Figure 1

US map showing location of selected airports

Figure 2

Number of selected airports reporting slippery weather, by day, for 2007

Figure 3

Number of distal radius fractures per day, by month, in the analysis cohort of Medicare beneficiaries in 2007

Figure 4

Incidence Rate Ratio of DRF by slipperiness score, as compared to slipperiness score of 0. The dotted line at 1 is the reference for no difference. Slipperiness scores of 5, 6, and 7 resulted in a significantly increased risk for DRF.

Figure 5

IRR of isolated (minor) DRF by slipperiness score. The dotted line at 1 is the reference for no difference. Slipperiness scores of 5, 6, and 7 resulted in a significantly increased risk for DRF.