Objectives: To determine whether performance decrements at night actually translate into worsened measures of quality of patient care in the emergency department (ED). Emergency physicians and healthcare workers are sleepier and less cognitively proficient at night than during the day. Despite a lack of data, medical errors have been attributed to these deficits, and pharmacologic solutions recently have been suggested.
Methods: The authors studied 36 months of emergency care and measured quality indicators, including early mortality (deaths occurring after arrival in the ED or within 48 hours of hospital admission), frequency of return after ED discharge, time to thrombolysis in acute myocardial infarction (AMI), frequency of aspirin use in AMI, and performance of endotracheal intubation. Comparisons were by time of day in eight-hour epochs.
Results: There were 345,000 patient encounters in the study period. The distribution in time was determined for 25,079 sampled ED visits, 3,666 admissions, and 507 early deaths. Estimated early mortality was 0.5% (95% CI = 0.0 to 1.0%) greater at night compared with during the day. There was no effect of time of day on 1,828 returns with admission after ED discharge. In 257 patients who received thrombolytics for AMI, mean time-to-treatment and frequency of aspirin use were not worse at night. In 443 emergent endotracheal intubations, there was no difference at night in the duration or number of attempts required, or in protocol adherence.
Conclusions: Quality indicators used in this study do not demonstrate marked deficits in patient care occurring at night. A very small, but measurable, increase in early mortality was identified. Improved measures to counter circadian disruption warrant study but may result in minimal improvements in patient care.