Cutsforth-Gregory, Jeremy

A 49-year-old woman presented with a dorsal column-predominant sensory myelopathy secondary to superficial siderosis. She had Marfan syndrome and was found to have dural ectasia. Superficial siderosis results from subpial haemosiderin deposition due to chronic subarachnoid space bleeding, often from a dural pathology, such as a tear. Dural ectasia is common in Marfan syndrome, but superficial siderosis is not. Gait ataxia, often with hearing impairment, is a common clinical presentation of superficial siderosis. Patients may develop myelopathy, here being a pure sensory myelopathy with predominant dorsal column deficit. Meningeal diverticulae and superficial siderosis are both associated with cerebrospinal fluid (CSF) leaks. This patient had dural ectasia and meningeal diverticulae, but the CT myelogram found no CSF leak. Superficial siderosis should be considered in patients with sensory myelopathy. Lumbosacral dural ectasia, or less likely CSF leak, can cause superficial siderosis in people with Marfan syndrome.

Objectives To develop neurology scenarios for use with the Quality Improvement Knowledge Application Tool Revised (QIKAT-R), gather and evaluate validity evidence, and project the impact of scenario number, rater number and rater type on score reliability. Methods Six neurological case scenarios were developed. Residents were randomly assigned three scenarios before and after a quality improvement (QI) course in 2015 and 2016. For each scenario, residents crafted an aim statement, selected a measure and proposed a change to address a quality gap. Responses were scored by six faculty raters (two with and four without QI expertise) using the QIKAT-R. Validity evidence from content, response process, internal structure, relations to other variables and consequences was collected. A generalisability (G) study examined sources of score variability, and decision analyses estimated projected reliability for different numbers of raters and scenarios and raters with and without QI expertise. Results Raters scored 163 responses from 28 residents. The mean QIKAT-R score was 5.69 (SD 1.06). G-coefficient and Phi-coefficient were 0.65 and 0.60, respectively. Interrater reliability was fair for raters without QI expertise (intraclass correlation = 0.53, 95% CI 0.30 to 0.72) and acceptable for raters with QI expertise (intraclass correlation = 0.66, 95% CI 0.02 to 0.88). Postcourse scores were significantly higher than precourse scores (6.05, SD 1.48 vs 5.22, SD 1.5; p < 0.001). Sufficient reliability for formative assessment (G-coefficient > 0.60) could be achieved by three raters scoring six scenarios or two raters scoring eight scenarios, regardless of rater QI expertise. Conclusions Validity evidence was sufficient to support the use of the QIKAT-R with multiple scenarios and raters to assess resident QI knowledge application for formative or low-stakes summative purposes. The results provide practical information for educators to guide implementation decisions.