Outcome in patients admitted outside regular hospital working hours: Does time until regular working hours matter?

Aims The aim of this study was to investigate whether stratifying patients according to the time period from admission to the start of regular working hours would help detect a weekend effect in acute stroke patients. Methods Ischemic stroke patients admitted between October 2002 and March 2012 were analyzed. Working hours were defined as 9:00-17:00 on weekdays. Patients were divided into those admitted during working hours (no-wait group) and three other groups according to the time from admission to working hours: <= 24 h (short-wait group), 24-48 h (medium-wait group), and >48 h (long-wait group). The modified Rankin Scale score and mortality at three-months were compared among the groups. Results Of 5625 patients, 3323 (59%) were admitted outside working hours. The proportion of patients with an mRS score 0-1 at three-months showed a decreasing trend with the time period before working hours: 47% (no-wait group), 42% (short-wait group), 42% (medium-wait group), and 38% (long-wait group), respectively (P < 0.001). When the no-wait group was used as a reference, the odds ratio for modified Rankin Scale score 0-1 was 0.88 (95% confidence interval, 0.75-1.04) in the short-wait group, 0.86 (0.69-1.07) in the medium-wait group, and 0.67 (0.53-0.85) in the long-wait group after adjusting for sex, age, premorbid mRS score, previous morbidity, stroke severity, and vascular risk factors. Mortality at three-months was not different between the no-wait group and the other groups. Conclusion A weekend effect might be evident if patients were stratified according to the time period from admission until working hours.