1.Estimating regional bone mineral density-based T-scores using clinical information; tools validated for postmenopausal women in Sri Lanka
Hewa Walpola Amila SEWWANDI SUBASINGHE ; Sarath EKAMWASAM ; Patrick BALL ; Hana MORRISSEY ; Eisha WAIDYARATNE
Osteoporosis and Sarcopenia 2020;6(3):122-128
Objectives:
This study aims to develop and validate a country specific osteoporosis risk assessing tool for Sri Lankan postmenopausal women.
Methods:
Community-dwelling postmenopausal women were enrolled to development (n ¼ 602) and validation (n ¼ 339) samples. Clinical risk factors (CRFs) of osteoporosis were assessed. Bone mineral densities (BMD) of femoral neck, total hip and lumbar spine were assessed by dual energy X-ray absorptiometry (DXA) scan. Radial ultrasound (US) bone scan was done. Linear regression analysis was performed in development sample considering regional BMDs as dependent and CRFs as independent variables. Regression equations were developed to estimate regional BMDs using best predictive CRFs.Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were assessed to validate the new tools.
Results:
Age, body weight and US T-scores showed positive correlations with BMDs of all 3 sites. Two osteoporosis risk assessing tools (OPRATs) were developed as OPRAT-1 and OPRAT-2. Prevalence of osteoporosis, in the validation sample was 74.3%. Sensitivity were high in both tools (OPRAT-1 and OPRAT-2; 83.2% and 82.5%) while specificity were moderate (44.8% for both). PPV of OPRAT-1 and OPRAT-2 were 79.5% and 81.2%. Both tools showed moderate NPV (OPRAT-1 and OPRAT-2; 51% and 47%).
Conclusions
Both OPRAT-1 and OPRAT-2 have high performance in screening postmenopausal women in Sri Lanka for risk of osteoporosis. OPRAT-2 is more convenient and can be used in any healthcare setting with limited resources to identify women who will be benefitted by DXA. OPRAT-1 can be used if the radial US facility is available.
2.Ability of FRAX Sri Lanka adjusted for trabecular bone score to discriminate between postmenopausal women with a recent fracture and without a fracture
Sarath LEKAMWASAM ; Madushani KARUNANAYAKA ; Vidumini KALUARACHCHI ; Manju CHANDRAN ; Hasanga RATHNAYAKE ; Sewwandi SUBASINGHE
Osteoporosis and Sarcopenia 2020;6(3):106-110
Objectives:
We evaluated the ability of fracture risk assessment tool (FRAX) Sri Lanka to discriminate between women with a recent fracture and without a fracture, when trabecular bone score (TBS) is added to the calculation.
Methods:
We studied 394 women without previous fractures and 87 women who underwent dual energy X-ray absorptiometry within 3 months after the first fragility fracture. Fracture probabilities (FP) were estimated with and without TBS using Sri Lankan FRAX model and their ability to discriminate those with and without fracture was tested.
Results:
Women without fractures had higher bone mineral densities (BMDs) and lower FPs, compared to those with a recent fracture. Area under curves of receiver operating characteristic for FPs unadjusted were not different from those adjusted for TBS. The odd ratios of FPs unadjusted were not different from those of adjusted. The FPs estimated with TBS were higher, hence the intervention thresholds (ITs) were higher compared to FPs estimated without TBS. Thirty-two percent of women without previous fracture were above the ITs and the inclusion of TBS increased this to 36%. The integrated discriminatory index analysis showed a 8% increase in the discriminatory slope.
Conclusions
The inclusion of TBS to Sri Lankan FRAX did not show an added advantage in discriminating between postmenopausal women with a recent fracture and without a fracture. TBS inclusion in fracture risk calculation among those without previous fractures, however, showed a marginal increase in the number of women above ITs.