Outcome measures

Primary outcome was the results of the patient safety culture measured by the culturally adapted Norwegian version of the HSOPSC. Our previously published results were compared with new data collected in 2017.^{32 34} The HSOPSC was originally developed by the US Agency of Healthcare Research and Quality.⁴ The 12 safety culture dimensions consist of 42 single items distributed as three or four items per dimension. The dimensions cover aspects of hospitals safety culture as: ‘Overall patient safety’, ‘Frequency of events’, ‘Unit managers support to patient safety’, ‘Organisational learning – continuous improvement’, ‘Teamwork in unit’, ‘Communication openness’, ‘Error feedback’, ‘Non-punitive’, ‘Adequate staffing’, ‘Hospital managers support to patient safety’, ‘Teamwork across units’, and ‘Handoffs and transitions’. Items are scored on 1–5 Likert scales (anchored at 1=‘strongly disagree’ to 5=‘strongly agree, or 1=‘never’ to 5=‘always’. Psychometric properties of the questionnaire items and safety culture dimensions have been reported to be sound at the individual, unit and hospital levels of analysis and can be used to assess hospitals’ patient safety culture.^{35 36} Secondary outcome was correlation between SSC fidelity and safety culture.