Reliability, validity and responsiveness of the Dutch version of the AOSpine PROST (Patient Reported Outcome Spine Trauma)

Abstract

Purpose: To validate the Dutch version of AOSpine PROST (Patient Reported Outcome Spine Trauma). Methods: Patients were recruited from two level-1 trauma centers from the Netherlands. Next to the AOSpine PROST, patients also filled out SF-36 for concurrent validity. Descriptive statistics were used to analyze the characteristics. Content validity was assessed by evaluating the number of inapplicable or missing questions. Also floor and ceiling effects were analyzed. Internal consistency was assessed by calculating Cronbach’s α and item-total correlation coefficients (itcc). Spearman correlation tests were performed within AOSpine PROST items and in correlation with SF-36. Test–retest reliability was analyzed using Intraclass Correlation Coefficients (ICC). Responsiveness was assessed by calculating effect sizes (ES) and standardized response mean (SRM). Factor analysis was performed to explore any dimensions within AOSpine PROST. Results: Out of 179 enrolled patients, 163 (91.1%) were included. Good results were obtained for content validity. No floor or ceiling effects were seen. Internal consistency was excellent (Cronbach’s α = 0.96, itcc 0.50–0.86), with also good Spearman correlations (0.25–0.79). Compared to SF-36, the strongest correlation was seen for physical functioning (0.79; p <.001). Also test–retest reliability was excellent (ICC = 0.92). Concerning responsiveness analysis, very good results were seen with ES = 1.81 and SRM = 2.03 (p < 0.001). Factor analysis revealed two possible dimensions (Eigenvalues > 1), explaining 65.4% of variance. Conclusions: Very satisfactory results were obtained for reliability, validity and responsiveness of the Dutch version of AOSpine PROST. Treating surgeons are encouraged to use this novel and validated tool in clinical setting and research to contribute to evidence-based and patient-centered care.