Development and validation of a disease model for postmenopausal osteoporosis.

UNLABELLED: This article describes the development of a model for postmenopausal osteoporosis (PMO) based on Swedish data that is easily adaptable to other countries. INTRODUCTION: The aims of the study were to develop and validate a model to describe the current/future burden of PMO in different national settings. METHODS: For validation purposes, the model was developed using Swedish data and provides estimates from 1990. For each year of the study, the "incident cohort" (women experiencing a first osteoporotic fracture) was identified and run through a Markov model using 1-year cycles until 2020. Health states were based on the number of fractures and death. Fracture by site (hip, vertebral, and non-hip non-vertebral) was tracked for each health state. Transition probabilities reflected site-specific risk of death and subsequent fractures. Bone mineral density (BMD) was included as a model output; model inputs included population size and life tables from 1970 to 2020, incidence of fracture, relative risk of subsequent fractures based on prior fracture, relative risk of death following a fracture by site, and BMD by age (mean and standard deviation). RESULTS: Model predictions averaged across age groups estimated the incidence of hip, vertebral, and other osteoporotic fractures within a 5% margin of error versus published data. In Sweden, the number of osteoporotic fractures is expected to rise by 11.5% between 2009 and 2020, with a shift towards more vertebral fractures and multiple fractures. CONCLUSION: The current PMO disease model is easily adaptable to other countries, providing a consistent measure of present and future burden of PMO in different settings.