The Singh index which is based on a plain radiograph has commonly used in assessing the grade of osteoporosis. We studied value of the Singh index in assessing the grade of osteoporosis by obtaining reliability of the Singh index and correlation between the Singh index and bone mineral density.

Six observers assessed radiographs of 60 patients suspected osteoporosis. The interobserver and intraobserver agreement of the Singh index were obtained by using kappa statistics. The bone mineral density of proximal femur was measured by dual energy X-ray absorptiometry in all patients, and then the results of bone mineral density were compared with those of Singh index by using percentage of variance.

The kappa values of interobserver agreement ranged from 0.28 to 0.76 (mean value: 0.45) and the strength of the agreement was moderate. The percentage of variance of BMD which was explained by Singh index was 7.1%.

The results of this study suggest that the Singh index has low clinical value in assessing the grade of osteoporosis