OBJECTIVES: This study aimed to investigate staff's perceptions of patient safety culture (PSC) in two Danish hospitals before and after an in situ simulation intervention.

DESIGN: A repeated cross-sectional intervention study.

SETTING: Two Danish hospitals. Hospital 1 performs emergency functions, whereas hospital 2 performs elective functions.

PARTICIPANTS: A total of 967 healthcare professionals were invited to participate in this study. 516 were employed in hospital 1 and 451 in hospital 2. Of these, 39 were trained as simulation instructors.

INTERVENTION: A 4-day simulation instructor course was applied. Emphasis was put on team training, communication and leadership. After the course, instructors performed simulation in the hospital environment. No systematic simulation was performed prior to the intervention.

MAIN OUTCOME MEASURES: The Safety Attitude Questionnaire investigating PSC was applied prior to the intervention and again 4 and 8 weeks after intervention. The proportion of participants with a positive attitude and mean scale scores were measured as main outcomes.

RESULTS: The response rate varied from 63.6% to 72.0% across surveys and hospitals. Baseline scores were generally lower for hospital 1. The proportion of staff with positive attitudes in hospital 1 improved by ≥5% in five of six safety culture dimensions, whereas only two dimensions improved by ≥5% in hospital 2. The mean scale scores improved significantly in five of six safety culture dimensions in hospital 1, while only one dimension improved significantly in hospital 2.

CONCLUSIONS: Safety attitude outcomes indicate an improvement in PSC from before to after the in situ simulation intervention period. However, it is possible that an effect is more profound in an acute care hospital versus an elective setting.