Cost effectiveness of screening perimenopausal white women for osteoporosis: bone densitometry and hormone replacement therapy

Long-term fracture prediction by bone mineral assessed at different skeletal sites

Bone mineral density (BMD) was measured at the lumbar spine and cervical and intertrochanteric regions of the proximal femur by dual-photon absorptiometry and bone mineral content was assessed at the distal and midradius by single-photon absorptiometry in an age-stratified random sample of 304 Rochester, Minnesota women aged 30-94 years. Over follow-up extending to 10 years (median 8.3 years), 93 women experienced 163 new fractures. After adjusting for age, these bone mineral measurements predicted the likelihood of any incident fracture due to moderate trauma, with relative hazards varying from 1.4 to 1.6 per SD decrease in baseline bone mineral. A 1 SD decrease in lumbar spine BMD increased the risk of a new vertebral fracture comparably to a 17 year increase in age; a 1 SD decrease in femoral BMD was comparable to a 13-14 year increase in age on the risk of a hip fracture. We conclude that bone mineral measurements made at a variety of skeletal sites can predict the occurrence for at least 8-10 years of moderate trauma fractures of the sort that might be related to osteoporosis.

The cost-effectiveness of treating hypertension in elderly people--an analysis of the Swedish Trial in Old Patients with Hypertension (STOP Hypertension)

OBJECTIVES

The aim of this study was to estimate the cost-effectiveness of antihypertensive treatment in elderly people based on the results of the Swedish Trial in Old Patients with Hypertension (STOP Hypertension).

DESIGN

The STOP Hypertension study was a randomized trial comparing active antihypertensive treatment with a placebo. The risk of stroke, cardiovascular disease and total mortality was significantly reduced in the actively treated group compared to placebo.

SETTING

One hundred and sixteen primary health care centres in Sweden.

SUBJECTS

A total of 1627 hypertensive patients aged 70-84. No patient was lost to follow-up.

INTERVENTIONS

Antihypertensive treatment with beta blockers and diuretics for a mean follow-up of 25 months.

MAIN OUTCOME MEASURE

The cost-effectiveness ratio estimated as the net cost (the treatment cost minus saved costs of reduced cardiovascular morbidity) divided by the number of life-years gained (the increase in life expectancy from treatment).

RESULTS

The cost per life-year gained was estimated as SEK 5000 for men and SEK 15,000 for women ($1 = SEK 6; 1 pound = SEK 10). The cost per life-year gained did not exceed SEK 100,000 in any of the sensitivity analyses.

CONCLUSIONS

It is concluded that treatment of elderly hypertensive patients with beta blockers and/or diuretics is cost-effective according to the results of the STOP Hypertension study.

Setting priorities in the new NHS: can purchasers use cost-utility information?

It could be argued that the success of the new NHS depends, to some extent, on the production of accurate cost-utility information. This raises questions about the quality of this information, whether it can be transferred from one study setting to another and whether such information can reasonably be used 'at the negotiating table'. The quality of some studies is open to question. Some agreement is needed on issues of principle and more work is required to make cost-utility analyses more applicable locally.

Economic evaluation of osteoporosis prevention

In this paper economic evaluation of osteoporosis prevention is discussed. So far economic evaluation in this area has been limited to cost-effectiveness analysis. Four cost-effectiveness analyses of osteoporosis prevention are reviewed. It is noted that the major problem with these studies is the lack of reliable and valid data to base the cost-effectiveness analyses on, which precludes clear-cut conclusions about the cost-effectiveness of osteoporosis prevention. The studies, however, form a basis for future cost-effectiveness analyses in this field and as new data become available it should be possible to improve the accuracy and precision of the analyses. Due to the methodological problems of cost-effectiveness analysis and the decision-maker approach to economic evaluation, it is also argued that the contingent valuation (CV) method of measuring willingness to pay should be tested in this area. The CV method can be used both to value an actual treatment and the outcome of that treatment and the resulting amount can be compared with the costs (including the costs of externalities) to carry out cost-benefit analysis. It is concluded that a lot of work remains to be done in this area before economic evaluations can give a real contribution to policy, but such work may well be worthwhile due to the importance of this public health problem.

Relationships between metacarpal morphometry, forearm and vertebral bone density and fractures in post-menopausal women

The relationships between metacarpal morphometric, vertebral and forearm density measurements and the prevalence of vertebral and peripheral fractures were examined in 239 postmenopausal women (median age 63, range 32-84 years). Metacarpal cortical area/total area ratio (CA/TA) was measured with needle calipers, forearm mineral density (FMD) by single photon absorptiometry and vertebral mineral density (VMD) by single energy quantitative computed tomography. Of the 239 subjects 97 had not suffered any fractures, 44 had at least one previous vertebral fracture but no peripheral fractures, 41 had a history of peripheral fracture but no vertebral fracture and 57 had suffered both peripheral and vertebral fractures. There were significant correlations between a single measurement of CA/TA and both FMD (r = 0.65, p < 0.001) and VMD (r = 0.41, p < 0.001). Similar correlations existed between the mean of multiple measurements of CA/TA and both FMD and VMD. CA/TA (p < 0.001), FMD (p < 0.001) and VMD (p < 0.001) were reduced in subjects who had suffered fractures, when compared with the no fracture group. The percentage of cases in each of the four fracture groups (vertebral fracture only, peripheral fracture only, peripheral and vertebral fracture, peripheral or vertebral fracture) misclassified with reference to the no fracture group were similar with CA/TA, FMD or VMD measurements. We suggest that metacarpal morphometry, which is widely available at relatively low cost, yields cross-sectional information about bone density and fracture risk, comparable with that obtained by forearm and vertebral densitometry.

Osteoporosis: assessment of bone loss and remodeling

Osteoporosis, the most common metabolic bone disorder, is a major health problem in older individuals, and especially in postmenopausal women throughout the world. It is characterized by low bone mass, structural deterioration, and an increased risk of fracture. The expected growth in the percentage of the world population over 65 years of age suggests that control of the chronic diseases of the elderly must be a major international priority. In order to design and implement appropriate prevention and treatment strategies for osteoporosis, it is necessary to assess the extent of the disease or condition in populations, and in individuals in a clinical setting. This review focuses on available and emerging techniques to measure bone mass or density, and on the role of biochemical markers of bone remodeling in the prediction of future bone loss. In order to prevent a disease that progresses without any obvious symptoms, it is important to determine not only the current status of bone mass and remodeling but also to develop methods to predict future bone loss. Different information is derived from each of the assessment approaches, and a combination of measures may be necessary to develop accurate predictive models.

Sometimes sensitive, seldom specific: a review of the economics of screening

As the policy relevance of screening has increased, the application of the techniques of economic evaluation to screening has become widespread. This paper critically reviews the literature, and in so doing, highlights several ways in which future evaluations might be improved. These include: the adoption of a broader perspective regarding the questions to be addressed and the relevant margins; a reconsideration of the nature of the benefits and how they might be valued; and a greater emphasis being placed upon the role of individual behaviour and its potential impact on the outcome of economic evaluations.

Fracture of the distal forearm as a forecaster of subsequent hip fracture: a population-based cohort study with 24 years of follow-up

OBJECTIVE

To determine the long-term risk of hip fracture following fracture of the distal forearm.

DESIGN

Registry-based cohort study comparing patients with a fracture of the distal forearm with a population-based cohort. FRACTURE COHORT: All women and men above 40 years of age with a radiologically verified fracture of the distal forearm during a 5-year period, 1968-1972, in all 1,126 women and 212 men. CONTROL COHORT: An equal number of population-based, age- and sex-matched control persons selected from a population register.

MEASUREMENTS

All cohort members were followed up individually through record linkage until the first hip fracture, emigration, death, or the end of 1991. The cohort members contributed a total of 40,832 person-years of observation, and altogether 365 cases of hip fractures were observed.

RESULTS

Both women and men with a fracture of the distal forearm ran an increased risk of sustaining a subsequent hip fracture. The overall relative hazard for the women was 1.54 and for men 2.27. The increased risk in the women was independent of age at inclusion, but that in the men was more pronounced in the younger age groups.

CONCLUSIONS

Patients with a fracture of the distal forearm run an increased risk of sustaining a subsequent hip fracture. They therefore appear to constitute a group in which appropriate prophylactic measures against osteoporosis and fractures should be considered.

Bone density at various sites for prediction of hip fractures. The Study of Osteoporotic Fractures Research Group

Women with low bone density in the radius or calcaneus are at increased risk of hip fracture. To see whether bone density of the hip measured by dual X-ray absorptiometry is a better predictor of hip fracture than measurements of other bones, we assessed bone density at several sites in 8134 women aged 65 years or more. 65 women had hip fractures during a mean follow-up of 1.8 years. Each SD decrease in femoral neck bone density increased the age-adjusted risk of hip fracture 2.6 times (95% CL 1.9, 3.6). Women with bone density in the lowest quartile had an 8.5-fold greater risk of hip fracture than those in the highest quartile. Bone density of the femoral neck was a better predictor than measurements of the spine (p < 0.0001), radius (p < 0.002), and moderately better than the calcaneus (p = 0.10). Low hip bone density is a stronger predictor of hip fracture than bone density at other sites. Efforts to prevent hip fractures should focus on women with low hip bone density.

Screening for osteoporosis by bone densitometry: a stratified intervention approach

We have performed computer modelling of the relationship between bone mass, age and hip fracture in a conditional probability model using a national population of 100,000 postmenopausal women aged 50 who have their bone density measured once. The computer model very closely reproduced the actual number of fractures in a Western Australian population. Intervention to bone loss completely in subjects with the lowest bone density (below 1 SD below the mean) would prevent 0.42 of a hip fracture per patient treated if the whole population were treated. Halving the rate of bone loss in the whole population would reduce hip fracture by two-thirds. These data suggest that hormone replacement therapy, which is the most effective therapy for preventing bone loss but which has the most side effects, should be focused on subjects with bone mass below 1 SD below the mean. The remainder of the population could be targeted with a public health campaign based on the lifestyle factors of increased dietary calcium and exercise which have been shown to slow but not stop bone loss.

Epidemiology of osteoporosis

Osteoporosis is a major public health problem through its association with age-related fractures. Although fracture risk at any skeletal site depends upon a complex interaction between bone strength and trauma, recent epidemiologic studies confirm that bone density is currently the best single predictor of future fracture. The increasing burden of osteoporotic fractures urgently requires effective preventive strategies aimed at maximizing peak bone density, preventing excessive bone loss, and reducing the risk of falls.

Targeted estrogen/progesterone replacement therapy for osteoporosis: calculation of health care cost savings

Osteoporosis is a crippling affliction in which bone mass decreases, making it more susceptible to fracture. In postmenopausal women it presents most often as a hip, spinal, or forearm fracture. Adult women face a 15% lifetime risk of a hip fracture, and the annual costs of hip fractures alone are estimated at $7.3 billion in the United States. Since the 1970s, estrogen/progestogen therapy has been recognized as an effective intervention that reduces the risk of fractures. Recently, the development of methods for accurately determining bone mass and thus helping to predict bone fracture risk has made this intervention attractive for use in a targeted population. This report analyzes the health care costs and calculates the cost savings of coupling bone mineral density screening at the time of menopause with long-term estrogen/progestogen therapy for those most at risk for developing fractures. The model assumes that a cohort of 100,000 American white women, aged 50, are screened for bone mineral density and that 90% of the high-risk group (density less than 0.85 g/cm3) and 70% of the mid-risk group (density between 0.85 and 1.00 g/cm3) elect to take hormone replacement therapy for 15 years. Based on calculations of the costs of screening and hormone replacement therapy, and the savings in cost of treatment and lost productivity from reduced fractures, it is estimated that the present value of savings in cost of illness for this cohort over a 40-year period is $5.1 million.(ABSTRACT TRUNCATED AT 250 WORDS)

Cost-utility in practice: a policy maker's guide to the state of the art

In recent years QALYs (quality adjusted life years) have achieved considerable fame or perhaps even notoriety in health services policy making. Yet little has been done to date to assess the potential benefit in policy terms of studies that have used cost-utility analysis (CUA). It was in recognition of this fact that this particular investigation was undertaken. An evaluation of 51 cost-utility studies is reported in the paper. Several criteria were applied to each study including aspects of technical and policy relevance. The main findings were: few studies had been undertaken; they were limited to few areas of health care; their technical execution was often of poor quality; the majority of studies used the empirical findings of health state valuations obtained from original developers of different quality of life techniques; and many claimed their results to be 'favourable' (i.e. efficient interventions). This claim, however, is misguided because individual results get fed into generalised QALY league tables which ignore the context of specific studies and use results not performed on a common basis. Consequently, the state of the applied art of CUA is currently open to considerable question.

Assessment of the risk of post-menopausal osteoporosis using clinical factors

OBJECTIVE

We wished to assess the predictive value of the main clinical risk factors for osteoporosis over a low vertebral bone mineral density.

DESIGN

A cross-sectional study was made of a cohort of peri and post-menopausal women (mean age, 54 years).

PATIENTS

One thousand, five hundred and sixty-five normal white women were selected from among the women referred to our menopause clinic for screening and prevention of osteoporosis.

MEASUREMENTS

Each woman had replied to a detailed standardized questionnaire including the main clinical risk factors and had her bone density measured using dual photon absorptiometry.

RESULTS

The predictive value for a low vertebral bone mineral density (2 SD below the normal young adult value) was assessed for 15 historical and anthropometric variables. Among these, age, age at menarche, weight, height, menopause and its duration, were independent predictors of a low bone mineral density, in a multiple logistic regression analysis. Odds ratios were calculated for each of these variables, weight, menopause and its duration being the three most influential variables. At best this model makes it possible to correctly classify 73% of women with a low bone mineral density and 66% of those with a normal bone mineral density. If this model is used for screening, it could possibly save 25% of bone densitometry examinations.

CONCLUSIONS

Direct bone densitometry remains indispensable to assess osteoporosis risk, since risk factors alone are not sufficient for accurate delineation of either low or normal bone mineral density.

Cost-effectiveness of hormone replacement therapy after the menopause

The net resource costs and net health benefits of treating perimenopausal women with hormone replacement therapy were evaluated within the framework of cost-effectiveness analysis. Data from the epidemiological literature were used to estimate changes in discounted life expectancy from hip fracture, ischaemic heart disease and breast cancer that are associated with hormone replacement therapy under a variety of assumptions. Economic data were used to estimate changes in total discounted costs that result from the use of hormone replacement therapy. For women with a previous hysterectomy, 10- and 15-year courses of unopposed oestrogen were evaluated. The baseline assumptions for unopposed oestrogen were that breast cancer incidence would be increased for current users by 36% and that deaths from ischaemic heart disease would be reduced by 50% relative to non-users. Under these assumptions, oestrogen replacement therapy was found to be cost-effective, with ratios ranging from $9130 to $12,620 per additional year of life saved. For women who have not had a hysterectomy, 10- and 15-year courses of oestrogen combined with progestin were evaluated. The baseline assumptions for combined therapy were that breast cancer incidence and ischaemic heart disease deaths were unaffected. Under these assumptions, combined therapy was more costly, with ratios ranging from $86,100 to $88,500. Unless combined therapy is found to confer protection against ischaemic heart disease, the most cost-effective strategies for women with no prior hysterectomy may involve screening perimenopausal women to detect women at highest risk of hip fracture followed by selective treatment.

Evaluating the benefits and risks of postmenopausal hormone therapy

The evidence that estrogen protects against coronary heart disease is biologically plausible, consistent, and strong. These benefits have not been established by a randomized trial, however, so that the degree of protection against heart disease might have been overestimated because estrogen users tend to be healthier than nonusers. A randomized trial to determine whether estrogen alone or in combination with progestin protects against coronary heart disease should be given a high priority. Progestins generally attenuate the effects of estrogen on the concentrations of HDLC. It is not known whether this effect also limits the beneficial effects of estrogen on the risk of coronary heart disease. Recent studies suggest that estrogen may protect against coronary heart disease in other ways besides favorably altering serum concentrations of lipoproteins and that progestins might not have adverse effects on the risk of heart disease. Currently, theoretical concerns that progestins might be harmful seem outweighed by the evidence that they protect against endometrial cancer in women who have a uterus. For these women, some may find the side effects of progestins to be so bothersome that they prefer to take estrogen alone. This approach is reasonable so long as the patient has periodic endometrial biopsies for early detection of pre-malignant or malignant endometrial changes. Women without a uterus should take estrogen alone. Women who take long-term estrogen therapy appear to have about a 30% greater chance of developing breast cancer. On the other hand, breast cancer that develops while taking estrogen therapy might have a slightly better prognosis. Quantitative comparisons of fatal conditions suggest that the benefits of long-term therapy outweigh the risks. But these comparisons assume that all causes of deaths are equally important and do not adequately take account of other psychologic and physical effects of hormone therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-trauma mortality in elderly women with low bone mineral density. Study of Osteoporotic Fractures Research Group

9704 ambulatory women aged 65 years or older were prospectively studied to determine whether low bone mineral density (osteopenia) was associated with mortality. Bone mineral density was measured at entry to the study by single-photon absorptiometry. 299 women died during a mean of 2.8 years' follow-up. Osteopenia was associated with increased non-trauma mortality, probably because it is a marker for several other adverse factors. Each standard deviation decrease in proximal radius bone mineral density (0.104 g/cm2) was associated with a 1.19-fold increase in mortality (95% confidence interval 1.04-1.36), adjusted for age and duration of follow-up. Diminished bone mineral density at the proximal radius was strongly associated with deaths from stroke (relative risk = 1.74; 95% CI 1.12-2.70), an association that was not confounded by history of previous stroke, hypertension, postmenopausal use of oestrogen, thiazide diuretic treatment, diabetes mellitus, and smoking. Most deaths in women with low bone mineral density are unrelated to the occurrence of fractures-an observation that should be taken into account when estimating the need for and cost-effectiveness of bone-density screening and fracture prevention programmes.