ABSTRACT
Low back pain is a multidimensional disorder that can originate from a variety of pain generators, including the sacroiliac (SI) joint. Although the Oswestry Disability Index (ODI) is often used in SI joint treatment studies, the effects of the SI joint on functional disability are likely different from those of other low back pain generators. Thus, we developed the Denver SI Joint Questionnaire (DSIJQ) and performed validation testing in patients (n=24) with SI joint-specific pain at baseline, +2 weeks, and +6 months. Psychometric analyses included test-retest reliability, internal consistency, content validity, convergent criterion validity, divergent criterion validity, and responsiveness. The DSIJQ showed good test-retest reliability (intraclass correlation coefficient=0.87), internal consistency (Cronbach's alpha=0.842), content validity (<30% floor/ceiling effects), convergent criterion validity (r=0.89; P<.001), and divergent criterion validity (r=-0.33; P=.12). The DSIJQ was correlated with performance on two physical function tests: Timed Upand-Go (r=0.53; P=.008) and 5 Minute Walk (r=-0.52; P=.009). The DSIJQ showed better responsiveness than the ODI (standardized response mean and effect size, 1.14 and 1.45 for DSIJQ and 0.75 and 0.81 for ODI). Overall, the DSIJQ performed well on all psychometrics. Importantly, we validated the DSIJQ with patients' ability to complete two tests of physical functioning. Moreover, the DSIJQ was more sensitive to changes in SI joint disability than the ODI. These psychometrics suggest the DSIJQ is appropriate for evaluating SI joint disability and detecting changes in disability after targeted SI joint treatment. [Orthopedics. 2023;46(6):345-351.].