Cost effectiveness of hormone therapy in women at high risks of fracture in Sweden, the US and the UK--results based on the Women's Health Initiative randomised controlled trial.

OBJECTIVE

The purpose of the study was to assess the cost effectiveness of hormone therapy (HT) for postmenopausal women without menopausal symptoms at an increased risk of fracture in Sweden, the UK and the US.

METHODS

Using a state-transition model, the cost effectiveness of 50 year old women was assessed based on a societal perspective and the medical evidence found in the Women Health Initiative (WHI) trials. The model had a lifetime horizon divided into cycle lengths of 1 year and comprised the following disease states: hip fracture, vertebral fracture, wrist fracture, breast cancer, colorectal cancer, coronary heart disease, stroke and venous thromboembolic events. An intervention was modelled by its impact on the disease risks during and after the cessation of treatment. The model required data on clinical effects, risks, mortality rates, quality of life weights and costs valid for Sweden, the UK and the US. The main outcome of the model was cost per QALY gained of HT compared to no treatment.

RESULTS

The results indicated that HT compared to no treatment was cost-effective for most sub-groups of hysterectomised women, whereas for women with an intact uterus without a previous fracture, HT was commonly dominated by no treatment. Fracture risks were the single most important determinant of the cost effectiveness results.

CONCLUSIONS

HT is cost-effective in women with a hysterectomy irrespective of prior fracture status. In women with an intact uterus, opposed HT was cost-effective in those with a prior vertebral fracture, but cost-ineffective in women without a prior vertebral fracture. Even though HT is found cost-effective for a selection of osteoporotic women, it is unlikely to be considered for first-line therapy for osteoporosis because bisphosphonates have shown a similar reduction in fracture risks but without an increased risk of adverse events.