Long-Term Reliability and Validity of the AO Spine PROST (Patient-Reported Outcome Spine Trauma)

Abstract

Study design: Cross-sectional validation study.

Objective: The aim was to validate the AO Spine Patient-Reported Outcome Spine Trauma (PROST) at a minimum of 12 months posttrauma and to evaluate patient characteristics, types of spine fractures, and treatment strategies as determinants of AO Spine PROST scores.

Summary of background data: The reliability and validity of the AO Spine PROST as a measure of health-related quality of life for more than 12 months after onset of spine trauma is unclear.

Materials and methods: Patients with a traumatic spine injury were recruited from a level-1 trauma center. They were asked to complete the AO Spine PROST, EuroQoL 5D-5L (EQ-5D-5L), and either Oswestry disability index (ODI) or neck disability index (NDI) for concurrent validity. Internal consistency was assessed by calculating the Cronbach α and item-total correlation coefficients. Test-retest reliability was evaluated using intraclass correlation coefficients. Spearman correlation tests were performed for the AO Spine PROST in correlation with the EQ-5D-5L, and either ODI or NDI. Determinants for AO Spine PROST score were analyzed using multivariate regression models.

Results: A total of 175 patients participated in the cross-sectional arm and 49 in the test-retest arm of the study. Median duration of follow-up was 94.5 months. No floor or ceiling effects were seen. Internal consistency was excellent (α=0.98, item-total correlation coefficient: 0.73-0.91) as well as test-retest reliability (intraclass correlation coefficient=0.81). Satisfactory correlations were seen for the EQ-5D-5L (0.76; P <0.001), ODI (0.69; P <0.001), and NDI (0.68; P <0.001) with the AO Spine PROST. Multivariate linear regression models showed that having ≥1 comorbidities, duration of return to work within the range of 7 to 43 months and no return to work were significant independent determinants for a worse AO Spine PROST score.

Conclusions: Very good long-term reliability and validity results were found for the AO Spine PROST.