Validation of disease activity and functional status questionnaires in spondyloarthritis.

OBJECTIVES: Patients naïve to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and to the Ankylosing Spondylitis Disease Activity Score (ASDAS) have voiced confusion in our clinics over the use of the term "AS" in these instruments. It is unknown whether these tools may be applied to other related forms of spondyloarthritis (SpA). The Bath Ankylosing Spondylitis Functional Index (BASFI) questionnaire also requires more definitive validation. We 1) validated the BASFI against a standard definition of disability; and 2) validated slightly modified versions of the BASDAI and ASDAS questionnaires that replace references to "AS" with the term "inflammatory arthritis" for use in non-AS SpA. METHODS: Adult patients with SpA enrolled in the Veterans Affairs Program to Understand the Longterm outcomes in Spondylo-ARthritis (PULSAR) completed the BASFI, BASDAI, ASDAS and altered versions of the BASDAI (PULSAR-modified Bath Disease Activity Index [PuBaDAI]) and ASDAS (PULSAR-modified Ankylosing Spondylitis Disease Activity Score [PuASDAS]). Spearman correlations and logistic regression were used to analyse the scores. RESULTS: The correlation between BASDAI and PuBaDAI and between ASDAS and PuASDAS scores was high (Spearman's rho=0.92, p<0.001 and Spearman's rho=0.85, p<0.001, respectively). The test-retest correlation of BASFI was also high (Spearman's rho=0.92, p<0.001). The BASFI (OR 1.67, 95% C.I. 1.12-2.47), ASDAS (OR 1.34, 95% C.I. 1.02-1.76) and PuASDAS (OR 1.62, 95% C.I. 1.07-2.49) predicted federally-determined disability. CONCLUSIONS: Preliminary data suggest that BASDAI and ASDAS scores correlate well with modified forms of these questionnaires and that the ASDAS, PuASDAS and BASFI are associated with disability.

Validation of the osteoporosis self-assessment tool in US male veterans.

The osteoporosis self-assessment tool (OST) is a screening instrument that uses age and weight as parameters to predict the risk of osteoporosis. This study was designed to evaluate OST in predicting osteoporosis in males. Male veterans aged 50yr and older with no prior diagnosis of osteoporosis and no prior bone densitometry (dual-energy X-ray absorptiometry [DXA]) testing were eligible for the study. Sociodemographic information, medical history, and risk factors for osteoporosis were recorded. Anthropometric measurements were taken and DXA testing performed. The OST index for each subject was calculated and predictive values and receiver operating characteristic (ROC) curves were evaluated for OST and osteoporosis. Five hundred eighteen subjects underwent DXA, 92 (17.8%) had osteoporosis, 281 (54.2%) had low bone mass, and 145 (28.0%) had normal bone mineral density. The OST index ranged from -8 to 23 with a mean of 4 (standard deviation ± 4.3). An OST index of 6 or lower predicted osteoporosis with a sensitivity of 82.6%, specificity of 33.6%, and an area under the curve for the ROC curve of 0.67. OST index performed better in non-Hispanic whites and males >65 yr. OST predicts osteoporosis with moderate sensitivity and poor specificity in men.