Osteoporosis risk assessment and ethnicity: validation and comparison of 2 clinical risk stratification instruments.

BACKGROUND

Dual energy x-ray absorptiometry (DXA), coupled with early treatment, may reduce morbidity and mortality associated with osteoporosis. Clinical tools to enhance selection of women for DXA screening have not been developed or validated in an ethnically diverse population.

OBJECTIVE

To compare the performance of the osteoporosis risk assessment instrument (ORAI) and the simple calculated osteoporosis risk estimation (SCORE) instrument across 3 racial/ethnic groups to identify women who would benefit from DXA scans.

DESIGN

Blinded comparison of the instruments in a cross-sectional sample.

PARTICIPANTS

Two-hundred twenty-six postmenopausal women were recruited from a university-based family medicine clinic. Women with a prior diagnosis of osteoporosis or those taking bone active medications were excluded.

MEASUREMENTS

Participants completed a questionnaire that contained the ORAI and the SCORE questions; 203 completed a DXA scan.

RESULTS

The sensitivity and specificity for the ORAI (0.68, [0.49 to 0.88, 95% CI]; 0.66, [0.59 to 0.73, 95% CI]) and the SCORE instrument (0.54, [0.34 to 0.75, 95% CI]; 0.72, [0.65 to 0.78, 95% CI]) differed significantly from previous reports. Overall, the accuracy of the ORAI (66.5%) and SCORE instrument (70.0%) were similar (McNemar's test P value = .37). The accuracy between instruments differed significantly in African-American women (McNemar's test, P value <.001). In African Americans, the SCORE instrument correctly identified more women without osteoporosis, but missed 70% of those with osteoporosis.

CONCLUSIONS

The performance of the ORAI and SCORE instrument differed significantly from previous reports. Although both can reduce the use of DXA scans for screening for osteoporosis, lower sensitivities resulted in underrecognition of osteoporosis and may limit their clinical usefulness in an ethnically diverse population.