The work contained in this thesis explores the economic issues of screening women, and the subsequent use of hormone replacement therapy (HRT), for the prevention of osteoporosis. The thesis is divided into five sections. In the first section the background to the problem is described as are the relevant economic evaluation techniques. In addition, the relevant economic literature is reviewed. The second section of the thesis, contains the results of research aimed at estimating the costs of population screening followed by treating the women at highest risk. The three chapters in this section address the following issues: estimating total screening costs; developing an economic definition of at risk status; and describing the HRT compliance rate after screening and its associated costs. In the third section the consequences of screening are examined. Hence, the osteoporosis risk profile of non attenders is described and the effects of HRT on women's quality of life is explored. Finally, this section is completed with a study looking at the predictive value of bone density screening. The fourth section is a synthesis of all the costs and consequences described in the preceding sections with relevant additional information from the literature. This section shows that screening perimenopausal women will be very expensive in terms of cost per quality adjusted life years (QALY) gained. In contrast, screening women and treating them when they are aged 70 appears to generate a relatively low cost per QALY. The final, fifth section, of the thesis describes outstanding research issues which need to be addressed before any screening programme is implemented.