Validation of the AO Spine CROST (Clinician Reported Outcome Spine Trauma) in the clinical setting

Purpose: To evaluate feasibility, internal consistency, inter-rater reliability, and prospective validity of AO Spine CROST (Clinician Reported Outcome Spine Trauma) in the clinical setting. Methods: Patients were included from four trauma centers. Two surgeons with substantial amount of experience in spine trauma care were included from each center. Two separate questionnaires were administered at baseline, 6-months and 1-year: one to surgeons (mainly CROST) and another to patients (AO Spine PROST—Patient Reported Outcome Spine Trauma). Descriptive statistics were used to analyze patient characteristics and feasibility, Cronbach’s α for internal consistency. Inter-rater reliability through exact agreement, Kappa statistics and Intraclass Correlation Coefficient (ICC). Prospective analysis, and relationships between CROST and PROST were explored through descriptive statistics and Spearman correlations. Results: In total, 92 patients were included. CROST showed excellent feasibility results. Internal consistency (α = 0.58–0.70) and reliability (ICC = 0.52 and 0.55) were moderate. Mean total scores between surgeons only differed 0.2–0.9 with exact agreement 48.9–57.6%. Exact agreement per CROST item showed good results (73.9–98.9%). Kappa statistics revealed moderate agreement for most CROST items. In the prospective analysis a trend was only seen when no concerns at all were expressed by the surgeon (CROST = 0), and moderate to strong positive Spearman correlations were found between CROST at baseline and the scores at follow-up (r_s = 0.41–0.64). Comparing the CROST with PROST showed no specific association, nor any Spearman correlations (r_s = −0.33–0.07). Conclusions: The AO Spine CROST showed moderate validity in a true clinical setting including patients from the daily clinical practice.