Incidencia, riesgo y evolucion de las fracturas osteoporoticas de cuello de femur en las mujeres en España, a partir de un modelo de Markov.

The objective of the study is to estimate osteoporotic hip fracture incidence rates, by age and gender, and lifetime fracture risk of women of different age groups over 45 in Spain, and to determine the expected number of fractures and fracture-related person-years of functional impairment, as a basis for estimating the social costs of osteoporosis in Spain and the avoided costs of fractures in future cost-effectiveness analyses. The natural history of disease, recognised from fractures, is described using a Markov model and Monte Carlo simulations. Four cohorts of 10.000 women, each of a different age group, were simulated. Data were obtained from six hospitals of different size and geographical setting, to allow for diferences in hospital service structure. Patients included were all new cases of hip fracture who were attended in those hospitals in 1995. Results are extrapolated to the spanish population based on 1991 census. Results predict in the group of women aged 50 an over in Spain 968.000 osteoporotic hip fractures during their remainig lifetime, with a total amount of 1.013.000 fractures. Some 135.000 will become functionally impaired due to the fractures, acconting for 1.177.000 person-years of functional impairment. From a prevalence point of view, the estimated 23.631 hip fractures ocurred in Spain en 1995, with an average lenth of hospital stay of 18 days, at a unit cost in the acute phase of 850.000 pta, yield an annual direct hospital cost of the acute process of sligthly over 20.000 million pta. The study provides a prototipe for estimating avoided costs of fractures in future cost-effectiveness analyses.