The Development and Validation of a Quality Assessment and Rating of Technique for Injections of the Spine (AQUARIUS)

Background and Objectives: Systematic reviews evaluate the utility of procedural interventions of the spine, including epidural steroid injections (ESIs). However, existing quality assessment tools either fail to account for proper technical quality and patient selection or are not validated. We developed and validated a simple scale for ESIs to provide a quality assessment and rating of technique for injections of the spine (AQUARIUS). Methods: Seven experts generated items iteratively based on prior ESI technique studies and professional judgment. Following testing for face and content validity, a 17-item instrument was used by 8 raters from 2 different backgrounds to assess 12 randomized controlled trials, selected from 3 different categories. Using frequency of assessment, a 12-item instrument was also generated. Both instruments underwent reliability (intraclass correlation coefficient), validity (ability to distinguish low, random, and high study categories), and diagnostic accuracy (receiver operating characteristics) testing. Results: Both 17- and 12-item instruments were scored consistently by raters regardless of background, with overall intraclass correlation coefficients of 0.72 (95% confidence interval [CI], 0.53-0.89) and 0.71 (95% CI, 0.51-0.89), respectively. Both instruments discriminated between clinical trials from all 3 categories. Diagnostic accuracy was similar for the 2 instruments, with areas under receiver operating characteristic curves of 0.89 (95% CI, 0.82-0.96) and 0.90 (95% CI, 0.82-0.97), respectively. Conclusions: The instrument in both 17- and 12-item formats demonstrates good reliability and diagnostic accuracy in rating ESI studies. As a complement to other tools that assess bias, the instrument may improve the ability to evaluate evidence for systematic reviews and improve clinical trial design.