The effectiveness of bone density measurement and associated treatments for prevention of fractures. An international collaborative review

Development of the International Network of Agencies for Health Technology Assessment

Objectives: To describe the development of the International Network of Agencies for Health Technology Assessment (INAHTA) and its activities.

Methods: Review of literature material and other documents produced by or relating to INAHTA.

Results: INAHTA includes organizations that provide health technology assessment (HTA) advice to governments and receive most of their funding from public sources. In early 2009, there were forty-six members from twenty-seven countries, including both national and regional agencies. Interaction with other organizations includes links to Health Technology Assessment International (HTAi), the European Union Network for Health Technology Assessment (EUnetHTA), PAHO (the Pan American Health Organization, and the World Health Organization (WHO). An important feature of INAHTA is the routine interaction of its members with public sector decision makers. Output from the network has included guidelines and frameworks on HTA, reports of surveys, and joint projects.

Conclusions: INAHTA has developed as a global point of contact and information for those with interests in HTA.

Health technology assessment in Catalonia: An overview of past and future perspectives

Objectives:The current and past situation of health technology assessment (HTA) in Catalonia is presented in this study.

Methods:The approach used here is a historical review of facts and landmarks.

Results:Spain has undergone radical change in many aspects, but the changes in healthcare provision have been major indeed. Catalonia has had the ability to benefit from these changes and has been able to build upon professionals' experience and expertise to development a consistent HTA network and continuous evaluation paradigm. The early involvement of the Catalan Agency for Health Technology Assessment (CAHTA) in several relevant HTA international initiatives and the relationship of CAHTA and Research with other HTA agencies in Spain is also stressed.

Conclusions:HTA is currently of common use in Catalonia for decision making at different levels. Now emphasis has to be put on the coming challenges that the HTA community will have to face in the coming years: uncontrolled demand, capacity scarcity, a rapidly evolving knowledge frontier, and insufficient input from the economic sphere into evaluations.

[Osteopenia in primary health care patients: ¿do we need to be more rigorous?]

AIM

To describe the treatment prescribed to osteopenic women seen at an urban primary health care centre and the treatment compliance of those patients with a prescription of calcium and/or vitamin D.

MATERIALS AND METHOD

Cross-sectional study, osteopenic women diagnosed by bone densitometry between February 2005 and January 2006 (n=121). Clinical history review: demographic information; previous clinical history of bone fracture, type of fracture; parental history of fractures; tobacco use; osteoporosis-related medication or disease; dietary and sun exposure assessment; calcium, vitamin D and raloxiphene/bisphosphonates prescription; mean daily dose of calcium and vitamin D supplements collected at the pharmacy by patients. Analysis of treatment prescription and compliance according to the information collected was performed.

RESULTS

Mean age, 61.9±9.1 years; 90.7% post-menopausic. The dietary assessment was performed in 30.5% of the women included in the study. The drug prescription was as follows: calcium 74.6%, vitamin D 68.6% and raloxiphene/bisphosphonates 16.1%. All drug prescriptions were associated with lower T-score values. The patient's compliance of calcium supplements has been calculated as mean of 423.8±321.7 mg/day, and 343.1±225.9 IU of vitamin D; with no association with any of the studied variables.

CONCLUSIONS

We identified greater drug prescription in those patients with a lower T-score. The clinical history of previous fracture did not show association with drug prescription nor a better compliance. There was a lack of information about relevant issues in the clinical history of the osteopenic women included in the study. The patient's compliance of calcium and vitamin-D supplements is very variable.

Validation of OSIRIS, a prescreening tool for the identification of women with an increased risk of osteoporosis

According to the recent recommendations of the European Community and the World Health Organization, identification of risk factors for fracture or low bone mineral density (BMD) should help health professionals to make a better use of bone densitometry. This includes helping patients to modify their behaviour and act on modifiable risk factors (correction of low calcium intake and vitamin D deficiencies, etc.) and also to provide evidence-based guidance for starting a treatment when necessary. In this context, we previously developed a clinical scoring index, OSIRIS (OSteoporosis Index of RISk), for classifying women into three categories of risk of osteoporosis. In order to evaluate the discriminatory performance of OSIRIS, we performed the present prospective study in a sample of 889 postmenopausal women from France. The osteoporosis risk depends on the OSIRIS category. Thus, 62% of women in the 'high-risk' category (OSIRIS < or = -3) were osteoporotic, compared to 34% of women in the 'intermediate-risk' category (OSIRIS ranged between -3 and +1) and only 16.8% of women in the 'low-risk' category (score OSIRIS > 1). These results might contribute to the development of more efficient screening strategies for osteoporosis. The patients in the low-risk category do not require immediate BMD testing; women with 'intermediate risk' have to be carefully followed by their doctor with BMD testing decided on a case-by-case basis; for those within the high-risk category, treatment may be initiated immediately and BMD testing performed either to assess the efficacy of the treatment or to increase the long-term compliance of the patient. In conclusion, for clinical practice, a user-friendly tool has been developed. This tool, called OSIRIS, as far as a simple rule allows, identifies the level of osteoporosis risk in women.

Superiority of age and weight as variables in predicting osteoporosis in postmenopausal white women

Identification of women at risk for osteoporosis is of great importance for the prevention of osteoporotic fractures. Routine BMD measurement of all women is not feasible for most populations, hence identification of a high-risk subset of women is an important element of effective preventive strategies.

METHODS

We identified 959 postmenopausal non-Hispanic women aged 51 years and above from the NHANES III study to assess the relative contribution of risk predictors for low BMD at the whole proximal femur and the femoral neck regions. Based on recognized risk factors for osteoporosis identified by a systematic literature search, we ran several multiple linear regression models based on the results of preceding bivariate analyses. We show several models based on their explanatory ability assessed by adjusted r(2), ROC, and C-value analyses rather than on the coefficients and P values. We furthermore examined the sensitivity, specificity, and predictive values of our preferred models for various cutoff T-scores-the choice of which will vary depending on different study goals and population characteristics.

RESULTS

Age and weight were by far the most informative predictors for low bone mineral density out of a list of 20 candidate risk predictors. Our preferred prediction models for the two regions hence contained only two variables: i.e., age and measured weight. The resulting parsimonious model to predict BMD at whole proximal femur had an adjusted r(2) of 0.43, an area under the ROC curve of 0.85, and a C-value of 0.70. Similarly, prediction for BMD at the femoral neck had adjusted r(2), area under the curve, and C-value of 0.39, 0.83, and 0.66, respectively.

CONCLUSIONS

The model equations, predicted T-score = -1.332-0.0404 x (age) + 0.0386 x (measured weight) and predicted T-score = -1.318-0.0360 x (age) + 0.0314 x (measured weight) for whole proximal femur and femoral neck, respectively, can be used in field conditions for screening purposes. More complex prediction equations add little explanatory power. Based on the study goals and the population characteristics, specific cutoff T-scores have to be decided before using these equations.

[Technology assessment in health care: bone densitometry and alternative therapies in post-menopausal osteoporosis]

This article briefly presents the target factors and methods for summarizing evidence employed in a technological evaluation, as well as the underlying logic in their elaboration and utilization in the field of public health. The example is post-menopausal osteoporosis, analyzing the current timeliness of disseminating bone densitometry and technologies to combat osteoporosis in Brazil Available studies on the effects of the respective technologies were reviewed according to the recommended methodology in order to produce a synthesis of the scientific evidence, updated and applied in Brazil. Preliminary cost-effective analyses of different alternatives for intervention (as compared to traditional care) are presented, considering women in and around menopause and at 65 years of age. Despite the optimistic hypotheses, the incremental cost estimates per averted fracture were high, all above R$ 10,000 for any of the various intervention alternatives, as compared to a mean cost of fractures treated by traditional care estimated at less than R$ 2,000, suggesting that the implementation of any of the target alternatives in the SUS would be questionable according to both efficiency criteria in the use of resources as well as equity.

Change in bone mass distribution induced by hormone replacement therapy and high-impact physical exercise in post-menopausal women

The purpose of this intervention trial was to determine whether changes in bone mass distribution could be observed in postmenopausal women following hormone replacement therapy (HRT) and/or high-impact physical exercise. Eighty healthy women, aged 50-57 years, at <5 years after the onset of menopause and with no previous use of HRT, were randomly assigned to one of four groups: HRT; exercise (Ex); HRT + Ex (ExHRT); and control (Co). HRT administration was conducted in a double-blind manner for 1 year using estradiol plus noretisterone acetate (Kliogest). The exercise groups participated in a 1 year progressive training program consisting of jumping and bounding activities. Subjects participated in two supervised sessions per week and were asked to perform a series of exercises at home 4 days/week. Bone measurements using a quantitative computed tomography scanner (Somatom DR, Siemens) were obtained from the proximal femur, midfemur, proximal tibia, and tibial shaft. Data were analyzed with a software program (BONALYSE 1.3) calculating density (g/cm(3)), cross-sectional area (CSA; mm(2)), and moments of inertia (I(max), I(min), I(polar)). In addition, the bone mass spectrum was determined as a function of the angular distribution around the bone mass center (polar distribution) and the distance from the bone mass center through the diaphyseal wall (radial distribution). After the 1 year period, there was an overall interaction of group x time in bone mineral density (BMD) at the proximal femur (p = 0.05) and tibial shaft (p = 0.035). Women in the ExHRT and HRT groups had increased proximal femur and tibial shaft BMD when compared with the change observed in the Co group (p = 0.024-0.011). The change was more pronounced in the cortical tibia, wherein the ExHRT group also differed from the Ex group (p = 0.038). No significant changes were found in bone CSA at any of the measured sites. The radial distribution indicated an increase of BMD in the endocortical part of the measured sites in the HRT and ExHRT groups and in the proximal tibia in the Ex group. The polar distribution showed that bone mass was redistributed in the anteroposterior direction. The changes in I(max), I(min), and I(polar) in the HRT and ExHRT groups differed from those in the Co group at the proximal femur, midfemur, and proximal tibia (p = 0.047-0.001). The Ex group also differed from the Co group in I(max) and I(polar) at the proximal tibia (p = 0.018 and 0.039, respectively). These results support the idea that HRT acts primarily at the bone-marrow interface. The exercise intervention chosen for this study contributed to the maintenance of bone mass. Our results suggest that both HRT and exercise have local effects on bone mass. The change in bone mass distribution induced by HRT and exercise may play an important role in the alteration of bone strength.

Brånemark implants and osteoporosis: a clinical exploratory study

BACKGROUND

Oral implant treatment on patients with poor jaw-bone texture has shown increased failure rates in series of studies.

PURPOSE

The purpose of the present study was to retrospectively follow patients with osteoporosis of the axial or appendicular skeleton, including the jaw bone, being subjected to oral implant treatment. The outcome of inserted implants, when using an adapted bone site preparation technique and extended healing periods, was evaluated.

MATERIALS AND METHODS

Based on data obtained from preoperative radiographs, patient medical history, and resistance of the jaw bone perceived during drilling, 14 of 16 patients were referred to the Osteoporosis Laboratory, Sahlgren University Hospital, Göteborg, Sweden, for bone density measurements. Two patients already had an established diagnosis of osteoporosis. Fourteen jaws in 13 patients (11 females, 2 males; mean age: 68 yr) were subsequently subjected to oral implant treatment with a total of 70 implants (Brånemark System) of various designs. The mean follow-up period was 3 years and 4 months (range: 6 mo-11 yr).

RESULTS

Osteoporosis of either the spine, the hip, or both regions was diagnosed in 14 patients, and osteopenia was diagnosed in 2 patients. Two implants failed, and the overall implant survival rate at the end of the study period was 97.0% for maxillae and 97.3% for mandibles. The marginal bone resorption at the 1-year follow-up concurs with the outcome of other studies, irrespective of the preoperative bone texture present.

CONCLUSION

The outcome of the present study showed that implant placement in patients in whom the average bone density showed osteoporosis in both lumbar spine and hip as well as poor local bone texture may be successful over a period of many years.

The Canadian SCORE questionnaire: optimizing the use of technology for low bone density assessment. Simple Calculated Osteoporosis Risk Estimate

The Simple Calculated Osteoporosis Risk Estimation (SCORE) questionnaire is a tool to assist physicians to identify women who might require bone densitometry. The purpose of this study was to develop a Canadian SCORE and to assess validity and reliability. Twenty sites enrolled 307 postmenopausal women ages 50-70 yr. SCORE results were compared to hip and lumbar spine bone density assessed by dual X-ray absorptiometry. Sensitivity and specificity of a range of SCORE cut-points were assessed in a receiver operating characteristics analysis to determine the optimal cut-point for SCORE. With low bone density defined as a T-score < or = -2.0, a SCORE cut-point of 6 in women ages 50-59 yr displayed a sensitivity of 0. 96, 95% confidence interval (CI) (0.89, 1.00), a specificity of 0.51, 95% CI (0.43, 0.58). In women ages 60-70 yr, a SCORE cut-point of 8 displayed a sensitivity of 0.90, 95% CI (0.80, 0.97) and a specificity of 0.20, 95% CI (0.11, 0.29). The test-retest reliability (intraclass correlation coefficient) was 0.95. SCORE performed better in women in their fifties than women in ther sixties. Older women require higher SCORE cut-points. The use of SCORE as an initial measure for identifying those at risk for osteoporosis may reduce costs by limiting unnecessary tests.