Development and Validation of a Brief Culture-of-Safety Survey

Culture of safety (COS) is recognized as a critical component of patient safety but can be burdensome to measure due to survey length. This project aimed to develop a shortened COS survey with comparable measurement properties to a validated 19-item instrument.

Item response theory (IRT) was used to reduce items from a 19-item COS survey at a 10-hospital health system. Using a 50% random sample, IRT was applied to evaluate survey question discrimination and information. Concepts from the key questions in each subdomain were reworded into a new abbreviated scale. Cognitive interviews with clinicians were conducted to validate reworded questions for adequacy, clarity, and consistency of interpretation.

The 19-item survey was reduced with IRT to 4 items. Cronbach's alpha for the 4-item IRT-derived scale was 0.80 (average inter-item covariance = 0.36) and was comparable to the original scale despite ∼75% reduction in items. Pearson correlation between the 4-item scale and the original scale was > 0.90. The 4-item scale demonstrated convergent validity. Results were replicated in a 50% random validation sample. Cognitive interviews revealed inadequacy of the shortened scale in assessing error-reporting culture. A fifth item was developed and qualitatively validated for this construct.

Using a mixed methods approach, a lengthy COS survey was condensed and revised to a brief 5-question survey with comparable measurement properties and respondent interpretation. A shorter instrument necessarily loses detailed insight into multiple aspects of safety culture, and organizations should consider trade-offs in choosing to develop a briefer survey.