Are annual fluctuations in hip fracture incidence dependent upon the underlying mortality rate?

There is substantial variation in hip fracture incidence rates from one yea r to the next. To determine whether this is related to varying mortality ra tes in the underlying population, we carried out an ecological analysis in Rochester and Olmsted County, Minnesota. In a given year, mortality in the general population was not related to hip fracture incidence nor did the fr acture incidence rates influence the overall death rate. There was a negati ve correlation between hip fracture incidence and mortality in the precedin g year among women, but not men; the trend was statistically significant am ong women less than 80 years of age. Both cervical and intertrochanteric hi p fractures in women had a similar relationship to mortality in the populat ion the year before. There was no consistent relationship between hip fract ure incidence and mortality rates two or three years previously. Although m any hip fractures occur in frail individuals near the end of life, patterns of mortality in the underlying population cannot account for the annual va riation in hip fracture incidence.