Revised FRAX®-based intervention thresholds for the management of osteoporosis among postmenopausal women in Sri Lanka

The This paper revised the fixed intervention thresholds (ITs) based on the Sri Lankan fracture risk assessment tool (FRAX) published in 2013 and introduced new ITs, hybrid and two-tier, aiming to help clinicians in the management of postmenopausal osteoporosis. The hybrid and two-tier ITs have a better discriminatory power than age-dependent and revised fixed ITs.IntroductionThis study revised the Sri Lankan FRAX (R)-based intervention thresholds (ITs) previously published in 2013.MethodAge-dependent ITs were estimated, from 50-80years with 5-year intervals, using a Sri Lankan FRAX (R) algorithm for a woman with a BMI of 24.8kg/m(2) and history of prior fragility fracture without other clinical risk factors. Data of 653 postmenopausal women were used in estimating fixed, hybrid, and two-tier ITs. ITs were determined using the ROC curve and partial Youden index. New ITs were validated using data of 356 postmenopausal women who underwent DXA and 62 women who had a recent fragility fracture. Women in the two groups (n=653 and n=356) came from the Southern Province and had undergone DXA in our state-owned tertiary care hospital as a part of their routine clinical assessment.ResultsThe mean (SD) age and BMI of the subjects (n=653) were 62 (8)years and 24.8 (1.2)kg/m(2), respectively. Age-dependent ITs of major osteoporotic fracture risk (MOFR) and hip fracture risk (HFR) ranged from 2.7 to 18% and from 0.4 to 7.1%. The best fixed ITs for women aged 50-80years were 9% for MOFR and 3% for HFR. In the hybrid method, MOFR of 6% and HFR of 2% were found appropriate for women aged <70years. These were combined with age-dependent ITs for women aged 70years and above. In the two-tier system, two sets of ITs were calculated (ITs of MOFR/HFR for women aged <70years and 70years were 6%/2% and 12%/5%, respectively). When age-dependent ITs were considered the reference standard, sensitivities of the fixed, hybrid, and two-tier ITs were 0.63, 0.73, and 0.74, respectively. The specificities were 0.76, 0.86, and 0.80 in the same order. Sensitivities of the age-dependent, fixed, hybrid, and two-tier ITs in identifying a woman with an incident fracture were 26%, 48%, 61%, and 61%, respectively.ConclusionsThe new fixed MOFR is slightly lower than the previous value and hybrid and two-tier ITs perform better than age-dependent and fixed ITs.