BackgroundThe Veterans Administration (VHA) launched an enterprise-wide High Reliability Organization (HRO) transformation effort in February 2019. Yet, many gaps exist in understanding the mechanisms through which HROs achieve positive outcomes. The goal of this paper is to assess content validity of Patient Safety Culture (PSC) scale through a secondary analysis of qualitative data collected from four purposively sampled VHA hospitals concurrently with the employee survey administered in 2019-2020. Methods: We used a concurrent triangulation mixed methods design secondary analysis of the qualitative data collected between 2019-2020 from a larger study that focused on understanding HRO implementation efforts at 4 of the 18 VHA HRO lead hospitals. We combined qualitative data from our summary qualitative reports with quantitative ratings in a cross-hospital matrix to explore the extent and manifestation of each of the PSC factors. Results: Scores were significantly different between the 4 hospitals for all four PSC factors. Twelve of the twenty PSC items (60%) significantly differed across the 4 hospitals. Despite the high rate of statistically significant differences in PSC scores, many differences were small. Qualitative data revealed supporting evidence for 16 of 20 PSC individual items, suggesting good coverage and content validity for the quantitatively derived PSC factors. Conclusions: PSC is a central pillar of HRO maturity. This study shows a newly developed VHA PSC factor had good content validity based on a mixed methods analysis. Future research is needed to better understand the relationship of PSC factors to HRO process and clinical outcomes.