Psychometric properties of the Hospital Survey on Patient Safety Culture: findings from the UK.

BACKGROUND Patient safety culture is measured using a range of survey tools. Many provide limited data on psychometric properties and few report findings outside of the US healthcare context. This study reports an assessment of the psychometric properties and suitability of the American Hospital Survey on Patient Safety Culture for use within the UK. METHODS A questionnaire survey of three hospitals within a large UK Acute NHS Trust. 1437 questionnaires were completed (37% response rate). Exploratory factor analysis, confirmatory factor analysis and reliability analyses were carried out to assess the psychometric performance of this survey instrument and to explore potential improvements. RESULTS Reliability analysis of the items within each proposed scale showed that more than half failed to achieve satisfactory internal consistency (Cronbach's α<0.7). Furthermore, a confirmatory factor analysis carried out on the UK data set achieved a poor fit when compared with the original American model. An optimal measurement model was then constructed via exploratory and confirmatory factor analyses with split-half sample validation and consisted of nine dimensions compared with the original 12 in the American model. CONCLUSION This is one of the few studies to provide an evaluation of an American patient safety culture survey using data from the UK. The results indicate that there is need for caution in using the Hospital Survey on Patient Safety Culture survey in the UK and underline the importance of appropriate validation of safety culture surveys before extending their usage to populations outside of the specific geographical and healthcare contexts in which they were developed.