Performance of the Khon Kaen Osteoporosis Study (KKOS) score for identifying osteoporosis in men.

OBJECTIVE The present study evaluated the diagnostic performance of Khon Kaen Osteoporosis Study (KKOS) score in identifying osteoporosis in men. MATERIAL AND METHOD This was a cross-sectional investigation in 230 men aged > or = 50 years. Bone mineral density (BMD) was measured at the femoral neck and lumbar spine by DXA (DPX-IQ densitometer LUNAR Corporation, Madison, Wisconsin, USA). The KKOS score was calculated for each man using his age and weight. Men with KKOS scores < or = -1 and > -1 were classified as "high risk" and "low risk", respectively. RESULTS The prevalence of osteoporosis in the entire sample was 17% and 7.4% (n = 39, 17) by femoral neck BMD and lumbar spine BMD, respectively. Using the KKOS score, 80 (34.8%) men were classified as "high risk" (KKOS score < or = -1). The proportion of high risk individuals increased with advancing age, ranging from 16.2% in the 50-65 age group to 64.8% in the > 65 age group. Using BMD from DXA as a gold standard, the overall sensitivity and specificity of KKOS in identifying osteoporosis was 72.5% and 73.2%, respectively. However; the sensitivity was higher at the lumbar spine (94.1% vs. 71.8%) than the femoral neck, while the specificity was comparable. The PPV of KKOS was 36%; and was lower at the lumbar spine (20%) compared to the femoral neck (35%). In the present study, men were classified "high risk" from KKOS, the risk (odds ratio; OR) of osteoporosis at the femoral neck and/or lumbar spine was 7.19 (95% CI: 3.34-15.44). However, the risk of osteoporosis was higher in the younger age (50-65 yr) group (OR: 10.29, 95% CI: 3.31-31.94) compared with the older age (> 65 yr) group (OR: 3.65, 95% CI: 1.12-11.91). CONCLUSION KKOS scoring system based on age and body weight, is a simple tool for clinicians to make a decision to further DXA testing for identifying osteoporosis in Thai men. This tool had a high sensitivity and specificity, but modest PPV.