Identification and Assessment of Outcome Measurement Instruments in Cauda Equina Syndrome: A Systematic Review

Study Design: This was a systematic review of surgically managed Cauda Equina Syndrome (CES) Outcome Measurement Instruments (OMI). Objective: A core outcome set (COS) defines agreed outcomes which should be reported as a minimum in any research study for a specific condition. This study identified OMIs used in the wider CES literature and compare these to the established CESCOS. Methods: To identify measurement methods and instruments in the CES surgical outcome evidence base, a systematic review was performed. Medline, Embase and CINAHL plus databases were queried. In addition, a secondary search for validation studies of measurement instruments in CES was undertaken. Identified studies from this search were subject to the COSMIN risk of bias assessment. Results: In total, 112 studies were identified investigating surgical outcomes for CES. The majority (80%, n = 90) of these OMI studies were retrospective in nature and only 55% (n = 62) utilised a measurement method or instrument. The remaining 50 studies used study specific definitions for surgical outcomes defined within their methods. Of the 59 measurement instruments identified, 60% (n = 38 instruments) were patient reported outcome measures. Only one validated instrument was identified, which was a patient reported outcome measure. The validated instrument was not used in any study identified in the initial search (to identify measurement instruments). Conclusions: This review highlights the wide heterogeneity of measurement instruments used in surgically managed CES research. Subsequently, there is need for consensus agreement on which instrument or instruments should be used to measure each core outcome for CES surgical outcomes.