Impact of nighttime and weekends on outcomes of emergency trauma patients: A nationwide observational study in Japan.

The impact of time of day or day of week on the survival of emergency trauma patients is still controversial. The purpose of this study was to evaluate the outcomes of these patients according to time of day or day of week of emergency admission by using data from the nationwide Japan Trauma Data Bank (JTDB). This study enrolled 236,698 patients registered in the JTDB database from 2004 to 2015, and defined daytime as 09:00 am to 16:59 pm and nighttime as 17:00 pm to 08:59 am, weekdays as Monday to Friday, and weekends as Saturday, Sunday, and national holidays. The outcome measures were death in the emergency room (ER) and discharge to death. In total, 170,622 patients were eligible for our analysis. In a multivariable logistic regression adjusted for confounding factors, both death in the ER and death at hospital discharge were significantly lower during the daytime than at nighttime (623/76,162 [0.82%] vs 954/94,460 [1.01%]; adjusted odds ratio [AOR] 0.79; 95% confidence interval [CI] 0.71-0.88 and 5765/76,162 [7.57%] vs 7270/94,460 [7.70%]; AOR 0.88; 95% CI 0.85-0.92). In contrast, the weekdays/weekends was not significantly related to either death in the ER (1058/114,357 [0.93%] vs 519/56,265 [0.92%]; AOR 0.95; 95% CI 0.85-1.06) or death at hospital discharge (8975/114,357 [7.85%] vs 4060/56,265 [7.22%]; AOR 1.02; 95% CI 0.97-1.06). In this population of emergency trauma patients in Japan, both death in the ER and death at hospital discharge were significantly lower during the daytime than at night, but the weekdays/weekends was not associated with outcomes of these patients.