TRENDS IN THE INCIDENCE OF HIP FRACTURE IN SIENA, ITALY, FROM 1980 TO1991

There is general agreement that the crude incidence of proximal femur (hip) fractures is rising in conjunction with the ageing of the underl ying population. To explore possible changes in hip fracture incidence over time we analysed all femoral fractures occurring in the county o f Siena from 1980 to 1991. Data were collected from hospital record ch arts of the Department of Orthopaedics, recording all hip fractures oc curring during the 12-year period. In this period, the mean resident p opulation in Siena was 238,369 inhabitants (aged 0 to 90+ years) and t he crude number of all femoral fractures was 2,238. However, in calcul ating incidence rates, only hip fractures occurring in the population aged over 50 years were considered. In this population, the number of hip fractures was 1,825 with a male/female ratio of 1:2.8. A time-seri es data analysis (temporal trend) of the incidence of hip fracture dur ing the 12-year period revealed a linear and significant (p < 0.001) t rend to increase, but only in males, with an annual increasing rate of 3.62 per 100,000 person-years. In the female population, the temporal analysis did not show any significant trend during the observation pe riod.