Cost-effectiveness of 3 versus 6 years of zoledronic acid treatment before bisphosphonate holiday for women with osteoporosis.

We evaluated the cost-effectiveness of recurrent periods of 3 versus 6 years of zoledronic acid treatment prior to 3-year bisphosphonate holidays for US postmenopausal women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5. We found that cycles of 3 years of treatment followed by holidays is likely to be the more cost-effective option. INTRODUCTION: We compared the effectiveness and cost-effectiveness of cycles of 3 years versus 6 years of zoledronic acid treatment prior to 3-year bisphosphonate holidays for US postmenopausal women with osteoporosis. METHODS: We developed an individual-level state-transition microsimulation cost-effectiveness model to compare treatment strategies over the lifetime of recurrent periods of 3 years of zoledronic acid followed by 3-year holidays (zoledronic acid 3/3), recurrent periods of 6 years of zoledronic acid followed by 3-year holidays (zoledronic acid 6/3), and no zoledronic acid treatment for women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5. RESULTS: Base-case analysis and all key parameter sensitivity analysis findings for every treatment initiation age evaluated (50, 60, 70, and 80) revealed that zoledronic acid 3/3 was consistently the most cost-effective strategy, assuming a willingness-to-pay of $100,000 per quality-adjusted life-year (QALY). In general, the zoledronic acid 3/3 and 6/3 strategies were relatively close in effectiveness (QALYs) over the lifetime; however, lifetime direct health care costs were on average approximately $2000 lower for the 3/3 strategy. Probabilistic sensitivity analysis results revealed that the zoledronic acid 3/3 strategy was favored in greater than 70% of the iterations for a willingness-to-pay threshold of $100,000/QALY for all treatment initiation ages evaluated. CONCLUSIONS: After 3 years of zoledronic acid treatment for postmenopausal women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5, taking 3-year holidays before restarting another treatment cycle is likely to be more cost-effective over the lifetime than cycles of 6 years of treatment prior to 3-year holidays.

Cost-effectiveness of five versus ten years of alendronate treatment prior to drug holiday for women with osteoporosis.

We performed a cost-effectiveness analysis comparing 5 versus 10 years of alendronate treatment prior to 5-year drug holiday for US postmenopausal women with hip BMD T-scores between - 2.5 and - 3.5. We found that for most postmenopausal women 5 years of treatment prior to drug holiday is the more effective and cost-effective option. INTRODUCTION: We performed a cost-effectiveness analysis to compare 5 versus 10 years of alendronate treatment prior to 5-year drug holiday for postmenopausal osteoporotic women. METHODS: We created an individual-level state-transition microsimulation model to compare 3 treatment strategies for US postmenopausal women with osteoporosis and femoral neck BMD T-scores between - 2.5 and - 3.5 at baseline: recurrent periods of 5 years of alendronate followed by 5 years of drug holiday (alendronate 5/5), recurrent periods of 10 years of alendronate followed by 5 years of drug holiday (alendronate 10/5), and no alendronate treatment. RESULTS: Base-case analysis revealed for women initiating treatment at ages 50, 60, and 70, the alendronate 5/5 strategy dominated (was more effective and less costly than) the alendronate 10/5 strategy and no treatment. For women age 80, the alendronate 10/5 strategy dominated. When assuming a lower relative risk of nonvertebral fracture during years 6-10 of alendronate treatment than the base-case assumption, the alendronate 10/5 strategy became the most cost-effective strategy even at younger treatment initiation ages. Probabilistic sensitivity analysis results supported the base-case findings; for treatment initiation ages of 50, 60, and 70, the alendronate 5/5 strategy was favored, whereas for treatment initiation age of 80, the alendronate 10/5 strategy was favored; however, there was uncertainty in these findings. CONCLUSIONS: After 5 years of alendronate treatment, younger postmenopausal women (ages 50-70) with osteoporosis would likely benefit from a drug holiday, whereas older women (age 80) are likely to benefit from treatment for 10 years before a drug holiday.

Systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for osteoporosis or low bone density.

UNLABELLED: We performed a systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for DXA-determined osteoporosis or low bone density. Commonly evaluated risk instruments showed high sensitivity approaching or exceeding 90% at particular thresholds within various populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. INTRODUCTION: The purpose of the study is to systematically review the performance of clinical risk assessment instruments for screening for dual-energy X-ray absorptiometry (DXA)-determined osteoporosis or low bone density. METHODS: Systematic review and meta-analysis were performed. Multiple literature sources were searched, and data extracted and analyzed from included references. RESULTS: One hundred eight references met inclusion criteria. Studies assessed many instruments in 34 countries, most commonly the Osteoporosis Self-Assessment Tool (OST), the Simple Calculated Osteoporosis Risk Estimation (SCORE) instrument, the Osteoporosis Self-Assessment Tool for Asians (OSTA), the Osteoporosis Risk Assessment Instrument (ORAI), and body weight criteria. Meta-analyses of studies evaluating OST using a cutoff threshold of <1 to identify US postmenopausal women with osteoporosis at the femoral neck provided summary sensitivity and specificity estimates of 89% (95%CI 82-96%) and 41% (95%CI 23-59%), respectively. Meta-analyses of studies evaluating OST using a cutoff threshold of 3 to identify US men with osteoporosis at the femoral neck, total hip, or lumbar spine provided summary sensitivity and specificity estimates of 88% (95%CI 79-97%) and 55% (95%CI 42-68%), respectively. Frequently evaluated instruments each had thresholds and populations for which sensitivity for osteoporosis or low bone mass detection approached or exceeded 90% but always with a trade-off of relatively low specificity. CONCLUSIONS: Commonly evaluated clinical risk assessment instruments each showed high sensitivity approaching or exceeding 90% for identifying individuals with DXA-determined osteoporosis or low BMD at certain thresholds in different populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments.

Performance of risk assessment instruments for predicting osteoporotic fracture risk: a systematic review.

UNLABELLED: We systematically reviewed the literature on the performance of osteoporosis absolute fracture risk assessment instruments. Relatively few studies have evaluated the calibration of instruments in populations separate from their development cohorts, and findings are mixed. Many studies had methodological limitations making susceptibility to bias a concern. INTRODUCTION: The aim of this study was to systematically review the literature on the performance of osteoporosis clinical fracture risk assessment instruments for predicting absolute fracture risk, or calibration, in populations other than their derivation cohorts. METHODS: We performed a systematic review, and MEDLINE, Embase, Cochrane Library, and multiple other literature sources were searched. Inclusion and exclusion criteria were applied and data extracted, including information about study participants, study design, potential sources of bias, and predicted and observed fracture probabilities. RESULTS: A total of 19,949 unique records were identified for review. Fourteen studies met inclusion criteria. There was substantial heterogeneity among included studies. Six studies assessed the WHO's Fracture Risk Assessment (FRAX) instrument in five separate cohorts, and a variety of risk assessment instruments were evaluated in the remainder of the studies. Approximately half found good instrument calibration, with observed fracture probabilities being close to predicted probabilities for different risk categories. Studies that assessed the calibration of FRAX found mixed performance in different populations. A similar proportion of studies that evaluated simple risk assessment instruments (≤5 variables) found good calibration when compared with studies that assessed complex instruments (>5 variables). Many studies had methodological features making them susceptible to bias. CONCLUSIONS: Few studies have evaluated the performance or calibration of osteoporosis fracture risk assessment instruments in populations separate from their development cohorts. Findings are mixed, and many studies had methodological limitations making susceptibility to bias a possibility, raising concerns about use of these tools outside of the original derivation cohorts. Further studies are needed to assess the calibration of instruments in different populations prior to widespread use.

Factors related to the use of bone densitometry: survey responses of 494 primary care physicians in New England.

Large population-based surveys have shown that approximately 30% of people over age 65 years have osteoporosis and that 17% of the population over 65 years will sustain a fracture during their lifetime. Many people with osteoporosis are never being evaluated even though effective treatments are available. We examined why primary care physicians order few bone mineral density scans. We conducted a cross-sectional survey of primary care physicians practicing in any of the six New England states. Target physician specialties included internal medicine, general practitioners/family physicians, and obstetrician-gynecologists who had a facsimile number listed with the American Medical Association. Demographics, practice characteristics, use of bone densitometry, and attitudes regarding osteoporosis, bone densitometry and health maintenance were assessed by questionnaire. Twelve percent (n=494) of the physicians responded to the questionnaire. Respondents were similar to non-respondents with respect to years of practice, training and geographical state, though they were more likely to be female (p < or =0.05). Respondents had a mean age of 51 years, and 51% were trained in internal medicine, 25% in general practice/family practice and 24% in obstetrics-gynecology. The mean number of self-reported bone densitometry referrals per month was 10+/-11, and 25% of respondents reported that they referred fewer than 4 patients per month. In adjusted logistic models, factors significantly associated with referring fewer than 4 patients per month were: training in internal medicine (odds ratio (OR) 2.0, 95% confidence interval (CI) 1.0-3.9) or general practice/family practice (OR 2.6, 95% CI 1.3-5.2) versus obstetrics-gynecology; practicing in an urban setting (OR 2.5, 95% CI 1.3-4.9) or rural/small town setting (OR 2.2, 95% CI 1.2-4.1) versus a suburban setting; spending less than 50% of professional time in patient care (OR 4.0, 95% CI 1.7-9.5); seeing the lowest proportion of postmenopausal women (OR 2.5., 95% CI 1.2-5.3); the belief that calcium and vitamin D are adequate to treat osteoporosis (OR 2.1, 95% CI 1.0-4.5); and the belief that osteoporosis treatment should not be based on bone density results (OR 3.2, 95% CI 1.7-6.1). Potentially modifiable physician beliefs and a number of practice characteristics are associated with low referral rates for bone densitometry. Educational strategies aimed at improving the use of bone density testing should consider these factors.

Instant vertebral assessment: a noninvasive dual X-ray absorptiometry technique to avoid misclassification and clinical mismanagement of osteoporosis.

The presence of a vertebral fracture significantly increases the risk of future fracture, classifies a patient with "clinical" osteoporosis, and usually results in treatment for osteoporosis. However, the majority of vertebral fractures are silent, and lateral X-rays (the standard method for identification) are not routinely obtained. Instant vertebral assessment (IVA), a technology that utilizes dual X-ray absorptiometry (DXA), provides rapid assessment of vertebral fractures and is highly correlated with vertebral fractures, as assessed on standard lateral spine X-rays. To assess the role of IVA in patient management, we examined standard bone mineral density (BMD) of the spine, total hip, and femoral neck and spine IVA by DXA in 482 participants screened for an osteoporosis study, who had no previous knowledge of vertebral fractures. Using World Health Organization (WHO) guidelines, subjects were classified using BMD at the spine, total hip, femoral neck, or any combination of these central sites. In addition, we considered subjects as osteoporotic if they had vertebral fractures independent of low bone density. We found that vertebral fractures assessed by IVA were present in 18.3% of asymptomatic postmenopausal women recruited for this study. The sensitivity of BMD alone to diagnose osteoporosis based on either a vertebral fracture or low BMD using WHO criteria ranged from 40 to 74%. This means that between 26 and 60% of osteoporotic individuals could have potentially been missed. Furthermore, 11.0-18.7% of clinically osteoporotic individuals would have been classified as normal by BMD criteria alone. We conclude that IVA is a useful adjunct in the clinical identification of osteoporosis and may prevent mismanagement of osteoporotic patients.

Precision and discriminatory ability of calcaneal bone assessment technologies.

To determine if measuring skeletal status at the calcaneus is a potentially valuable technique for diagnosing osteoporosis, we examined five calcaneal assessment techniques in 53 young normal women and 108 postmenopausal women with osteoporosis and compared these measurements to dual-energy X-ray absorptiometry (DEXA) at the calcaneus, hip, and spine. The five instruments, including single-energy X-ray absorptiometry (SEXA) and four quantitative ultrasound (QUS) instruments, were evaluated for precision, ability to discriminate osteoporotic from young normal subjects, and correlation to the other instruments. The coefficient of variation (%CV) for instrument, positioning, interobserver, and short-term precision of the five calcaneal instruments ranged from 1.34-7.76%, 1.63-7.00%, 1.84-9.44%, and 1.99-7.04%, respectively. The %CVs for positioning, interobserver, and short-term precision were similar for calcaneal DEXA, calcaneal SEXA, and stiffness (as measured by Achilles). The %CVs for instruments precision were similar between calcaneal DEXA and SEXA. The ability of the five calcaneal instruments to discriminate osteoporotic from young normal subjects was similar based on the analysis of area under the receiver operating characteristic curves (range 0.88-0.93) and equivalent to DEXA of the calcaneus and hip (0.88-0.93). The correlations between the measurements of five calcaneal instruments were strong (0.80 < or = r < or = 0.91, p < 0.001). These data suggest that although the precision is variable, the calcaneal QUS and SEXA instruments can discriminate between osteoporotic patients and young normal controls and appear to be a useful technique for assessment of osteoporosis.