The Impact of Nurse Working Hours on Patient Safety Culture: a Cross-national Survey Including Japan, the United States and Chinese Taiwan Using the Hospital Survey on Patient Safety Culture

Background: A positive patient safety culture (PSC) is one of the most critical components to improve healthcare quality and safety. The Hospital Survey on Patient Safety Culture (HSOPS), developed by the US Agency for Healthcare Research and Quality, has been used to assess PSC in 31 countries. However, little is known about the impact of nurse working hours on PSC. We hypothesized that long nurse working hours would deteriorate PSC, and that the deterioration patterns would vary between countries. Moreover, the common trends observed in Japan, the US and Chinese Taiwan may be useful to improve PSC in other countries. The purpose of this study was to clarify the impact of long nurse working hours on PSC in Japan, the US, and Chinese Taiwan using HSOPS.

Methods: The HSOPS questionnaire measures 12 sub-dimensions of PSC, with higher scores indicating a more positive PSC. Odds ratios (ORs) were calculated using a generalized linear mixed model to evaluate the impact of working hours on PSC outcome measures (patient safety grade and number of events reported). Tukey's test and Cohen's d values were used to verify the relationships between nurse working hours and the 12 sub-dimensions of PSC.

Results: Nurses working ≥60 h/week in Japan and the US had a significantly lower OR for patient safety grade than those working <40 h/week. In the three countries, nurses working ≥40 h/week had a significantly higher OR for the number of events reported. The mean score on 'staffing' was significantly lower in the ≥60-h group than in the <40-h group in all the three countries. The mean score for 'teamwork within units' was significantly lower in the ≥60-h group than in the <40-h group in Japan and Chinese Taiwan.

Conclusions: Patient safety grade deteriorated and the number of events reported increased with long working hours. Among the 12 sub-dimensions of PSC, long working hours had an impact on 'staffing' and 'teamwork within units' in Japan, the US and Chinese Taiwan.