Determining the cut-off point of osteoporosis based on the osteoporosis self-assessment tool, body mass index and weight in Taiwanese young adult women

A review on the performance of osteoporosis self-assessment tool for Asians in determining osteoporosis and fracture risk

The prevalence of osteoporosis in Asian countries is growing. An effective screening method will enable patients at risk for osteoporosis to receive early diagnosis and treatment, and avoid overcrowding the limited dual-energy x-ray absorptiometry (DXA) machines available in Asian countries. Many simple osteoporosis screening algorithms have been developed but they are not validated for use in Asian populations. osteoporosis self-assessment tools for Asians (OSTA), established using a multinational Asian cohort, is the first screening algorithm that caters for the Asian populations. It considers only body weight and age in the algorithm. It shows consistently high performance and sensitivity in identifying postmenopausal women at risk for osteoporosis in many Asian countries. Its usage has been expanded for identifying osteoporosis in men, as well as determining fracture risk for both sexes. However, the performance of OSTA is influenced by age, sex, ethnicity and site of BMD measurement to define osteoporosis. Its usage is also limited in individuals without apparent risk factors. These limitations should be noted by physicians considering the use of OSTA in clinical setting. As a conclusion, OSTA is a cost-effective measure for osteoporosis screening in primary healthcare setting.

Association between the Osteoporosis Self-Assessment Tool for Asians Score and Mortality in Patients with Isolated Moderate and Severe Traumatic Brain Injury: A Propensity Score-Matched Analysis

Background: The purpose of this study was to use a propensity score-matched analysis to investigate the association between the Osteoporosis Self-Assessment Tool for Asians (OSTA) scores and clinical outcomes of patients with isolated moderate and severe traumatic brain injury (TBI). Methods: The study population comprised 7855 patients aged ≥40 years who were hospitalized for treatment of isolated moderate and severe TBI (an Abbreviated Injury Scale (AIS) ≥3 points only in the head and not in other regions of the body) between 1 January 2009 and 31 December 2014. Patients were categorized as high-risk (OSTA score < -4; n = 849), medium-risk (-4 ≤ OSTA score ≤ -1; n = 1647), or low-risk (OSTA score > -1; n = 5359). Two-sided Pearson's chi-squared, or Fisher's exact tests were used to compare categorical data. Unpaired Student's t-test and Mann-Whitney U test were performed to analyze normally and non-normally distributed continuous data, respectively. Propensity score-matching in a 1:1 ratio was performed using NCSS software, with adjustment for covariates. Results: Compared to low-risk patients, high- and medium-risk patients were significantly older and injured more severely. The high- and medium-risk patients had significantly higher mortality rates, longer hospital length of stay, and a higher proportion of admission to the intensive care unit than low-risk patients. Analysis of propensity score-matched patients with adjusted covariates, including gender, co-morbidity, blood alcohol concentration level, Glasgow Coma Scale score, and Injury Severity Score revealed that high- and medium-risk patients still had a 2.4-fold (odds ratio (OR), 2.4; 95% confidence interval (CI), 1.39-4.15; p = 0.001) and 1.8-fold (OR, 1.8; 95% CI, 1.19-2.86; p = 0.005) higher mortality, respectively, than low-risk patients. However, further addition of age as a covariate for the propensity score-matching demonstrated that there was no significant difference between high-risk and low-risk patients or between medium-risk and low-risk patients, implying that older age may contribute to the significantly higher mortality associated with a lower OSTA score. Conclusions: Older age may be able to explain the association of lower OSTA score and higher mortality rates in patients with isolated moderate and severe TBI.

Association of Osteoporosis Self-Assessment Tool for Asians (OSTA) Score with Clinical Presentation and Expenditure in Hospitalized Trauma Patients with Femoral Fractures

Background: A cross-sectional study to investigate the association of Osteoporosis Self-Assessment Tool for Asians (OSTA) score with clinical presentation and expenditure of hospitalized adult trauma patients with femoral fractures. Methods: According to the data retrieved from the Trauma Registry System between 1 January 2009 and 31 December 2015, a total of 2086 patients aged ≥40 years and hospitalized for treatment of traumatic femoral bone fracture were categorized as high-risk patients (OSTA < -4, n = 814), medium-risk patients (-1 ≥ OSTA ≥ -4, n = 634), and low-risk patients (OSTA > -1, n = 638). Two-sided Pearson's, chi-squared, or Fisher's exact tests were used to compare categorical data. Unpaired Student's t-test and Mann-Whitney U-test were used to analyze normally and non-normally distributed continuous data, respectively. Propensity-score matching in a 1:1 ratio was performed using Number Crunching Statistical Software (NCSS) software (NCSS 10; NCSS Statistical Software, Kaysville, UT, USA), with adjusted covariates including mechanism and Glasgow Coma Scale (GCS); injuries were assessed based on the Abbreviated Injury Scale (AIS), and Injury Severity Score (ISS) was used to evaluate the effect of OSTA-related grouping on a patient's outcome. Results: High-risk and medium-risk patients were predominantly female, presented with significantly older age and higher incidences of co-morbidity, and were injured in a fall accident more frequently than low-risk patients. High-risk patients and medium-risk patients had a different pattern of femoral fracture and a significantly lower ISS. Although high-risk and medium-risk patients had significantly shorter lengths hospital of stay (LOS) and less total expenditure than low-risk patients did, similar results were not found in the selected propensity score-matched patients, implying that the difference may be attributed to the associated injury severity of the patients with femoral fracture. However, the charge of surgery is significantly lower in high-risk and medium-risk patients than in low-risk patients, regardless of the total population or the selected propensity score-matched patients. This lower charge of surgery may be attributed to a less aggressive surgery applied for older patients with high or medium risk of osteoporosis. Conclusions: This study of hospitalized trauma patients with femoral fracture according to OSTA risk classification revealed that high-risk and medium-risk patients had significantly higher odds of sustaining injury in a fall accident than low-risk patients; they also present a different pattern of femoral bone fracture as well as a significantly lower ISS, shorter hospital LOS, and less total expenditure. In addition, the significantly lower charge of surgery in high-risk and medium-risk patients than in low-risk patients may be because of the preference of orthopedists for less aggressive surgery in dealing with older patients with osteoporotic femoral bone fracture.

Optimal Analysis to Discriminate Males’ Osteoporosis With Simple Physiological Indicators

Males account for one third of global hip fracture patients, and their hip fracture-related mortality rate is higher than that of females. Scholars have primarily investigated self-evaluation indicators for elderly Caucasians and other ethnicities, and have rarely conducted large-scale cutoff point studies on Asian males. In this study, a large-scale database on bone mineral density (BMD) examinations was used to conduct a cutoff point study on males with osteoporosis. This study involved a retrospective research design. Males who accepted BMD examinations from 2009 to 2012 at a large teaching hospital in Taiwan were sampled in this study. This study used the database for analyzing effects with using osteoporosis self-assessment indicator, age, body weight, and body mass index (BMI) to discriminate osteoporosis in males, specifically focusing on accuracy, cutoff point, sensitivity, specificity, and positive and negative predictive values. Overall, receiver operating characteristic curve for the samples reached 70%. These cutoff points included: a body weight is less than 58.8 kg, BMI is 23 kg/m2, and the osteoporosis self-assessment score is −1.86, to identify osteoporosis. Involving body weight and BMI as optimal assessing indicators for assessing osteoporosis among males younger than 65 years, and the osteoporosis self-assessment tool was ideal for measuring males older than 65 years. Professional health staff should apply convenient, low-cost, and accurate evaluation tools that can assist Asian males in planning preventive osteoporosis strategies to avoid osteoporotic fractures and death.

Performance of the Osteoporosis Self-Assessment Tool for Asians (OSTA) in Screening Osteoporosis Among Middle-Aged and Old Women in the Chengdu Region of China

The purpose of this study was to assess the performance of an osteoporosis self-assessment tool for Asians (OSTA) for screening middle-aged and old healthy women in the Chengdu region of China. OSTA scores were used to evaluate the effect of age on the development of osteoporosis. A total of 15,752 healthy women older than 40 yr, who reside in the Chengdu region, were assigned to 9 age groups divided by 5-yr intervals. Bone mineral density of the lumbar vertebrae, L1-L4, and the left hip was measured with a GE Lunar Prodigy advance dual-energy X-ray absorptiometry system (GE Healthcare, Cincinnati, OH). All subjects were classified into 3 categories according to OSTA cutoff values. The OSTA values used to define the categories were ≥-1, >-4 and <-1, and ≤-4. The accuracy of the OSTA index was compared with T-scores measured by dual-energy X-ray absorptiometry at various skeletal sites. All statistical analyses were performed using SPSS, version 17.0 (SPSS, Inc., Chicago, IL). The detection rate of osteoporosis and osteopenia at the lumbar vertebrae and the femur was found to increase with age. Furthermore, the sensitivity of OSTA value for detection of osteoporosis also gradually enhanced with subject age. In contrast, the specificity gradually decreased with age. The sensitivity and negative predictive value of the OSTA index for detecting osteoporosis gradually increased with higher OSTA cutoff values, and the specificity and positive predictive value appeared to gradually decline. It was concluded that the OSTA is a useful screening tool to detect osteoporosis in middle-aged and old women in the Chengdu region of China. Furthermore, specific OSTA cutoff values should be selected for screening individuals who belong to different age groups.

Development and Validation of an Osteoporosis Self-Assessment Tool for Taiwan (OSTAi) Postmenopausal Women-A Sub-Study of the Taiwan OsteoPorosis Survey (TOPS)

Background

To develop an OSTAi tool and compare this with the National Osteoporosis Foundation recommendations in 2013 (NOF 2013) for bone mineral density (BMD) testing among Taiwan postmenopausal women.

Methods

Taiwan Osteoporosis Association (TOA) conducted a nationwide BMD survey by a bus installed with a dual energy X-ray absorptiometry (DXA) between 2008 and 2011. All of the participants completed questionnaire, which included demographics and risk factors of osteoporotic fracture in FRAX tool. We used the database to analyze potential risk factors for osteoporosis and followed the model by Koh et al. to develop a risk index via multiple variable regression analysis and item reduction. We used the index values to set up a simple algorithm (namely OSTAi) to identify those who need BMD measurement. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) was used to compare the sensitivity/specificity analysis of this model with that of recommendations by NOF 2013.

Results

A total of 12,175 Taiwan postmenopausal women enrolled in this survey. The index value was derived by age and body weight of the participants according to weighted odds of each risk factor and the selected cutoff value was set at “-1”. There are 6393 (52.5%) participants whose index value is below “-1” and whose risk of osteoporosis was 57.5% (3674/6393). The AUC for OSTAi and NOF 2013 were 0.739 (95% confidence interval (CI), 0.728–0.749, P<0.001) and 0.618 (95% CI, 0.606–0.630, P<0.001), respectively. The sensitivity and specificity of OSTAi, at the selected cutoff value of -1, and NOF 2013 to identify osteoporosis were 73.1%, 62.0% and 78.3%, 45.7%, respectively.

Conclusions

As OSTA for Asian populations, OSTAi is an useful tool to identify Taiwan postmenopausal women with osteoporosis, In comparison with NOF 2013, OSTAi may be an easier and better tool for referral to BMD measurement by DXA in this area.

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

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.