Background: Simple and effective methods are needed to identify
patients at risk for osteoporosis or osteoporosis-related fracture so that
they can be screened with use of dual x-ray absorptiometry and counseled for
treatment. Currently, we use a cumbersome survey assessing thirty-two risk
factors. A much simpler score based on the Osteoporosis Self-Assessment
Screening Tool (OST score) has been established as highly sensitive and
specific in women, but similar data are lacking for men. This score is
calculated by subtracting the age of the patient in years from the weight in
kilograms and multiplying the result by 0.2. Our goal was to test the
hypothesis that the OST score is more sensitive and specific than our
extensive risk-assessment survey in men.
Methods: Using axial dual x-ray absorptiometry analysis, we
evaluated a cohort of men who had either responded to our newspaper
advertisement or were seen as patients in our orthopaedic clinic. Patients
filled out the risk-assessment survey at the time of scanning. Osteoporosis
was defined as a T-score of —2.5 or less in the lumbar spine, hip, or
femoral neck.
Results: Twenty-seven (17%) of 158 white men, with a mean age of
67.5 years and a mean weight of 85.3 kg, had osteoporosis. After analysis of
the thirty-two risk factors, two remained as significant independent
predictors in the final multivariable model (p = 0.042 and p = 0.015). This
model had an area under the receiver operating characteristic curve of 0.68
(>0.70 is considered to provide acceptable discrimination). The OST scores
ranged from —6 (greatest risk) to 16 (least risk). With use of the OST
score to predict osteoporosis, the area under the receiver operating
characteristic curve was 0.76. The cutoff of an OST score of <2 provided
the largest area under the receiver operating characteristic curve (0.74),
with test characteristics for an OST score of <2 including a sensitivity of
85%, specificity of 64%, positive predictive value of 31%, and negative
predictive value of 96%.
Conclusions: The Osteoporosis Self-Assessment Screening Tool score
is superior to a broad risk-factor analysis in the identification of men at
risk for osteoporosis or osteoporotic fractures. We have found it simple to
use in our clinic to determine which patients should undergo dual x-ray
absorptiometry screening.
Level of Evidence: Diagnostic Level I. See Instructions
to Authors for a complete description of levels of evidence.