Inpatient Blood Draws Often Interrupt Sleep

It may be time to re-evaluate the practice of early morning blood draws for noncritical patients. Four out of 10 inpatient blood draws occur during early morning hours, according to data collected at Yale New Haven Hospital. Although early morning blood draws are often considered necessary to inform decisions during morning medical rounds, sleep interruptions may increase the risk of delirium and other adverse events particularly in older patients, the study authors said in a research letter in JAMA.

“This is not an issue at just one hospital,” said coauthor Harlan M. Krumholz, MD, SM, professor of medicine and public health and director of the Center for Outcomes Research (CORE) at Yale. “Our findings reflect an aspect of how inpatient hospital care is being delivered in modern medicine. A more patient-centered care would limit nonurgent tests during sleep hours.”

The researchers analyzed data on more than 5 million nonurgent blood draws extracted from electronic health records of all adult patients hospitalized at Yale New Haven Hospital (YNHH) between November 1, 2016, and October 31, 2019. They isolated data on nonurgent blood draws by excluding data on blood draws performed in the emergency department, critical care units, step-down units, or during the first 24 hours after admission.

The final study sample included 5,676,092 blood draws from 79,347 adult patients. Nearly 40% of samples were drawn between 4 am and 7 am (Table).

Table. Timing of Nonurgent Blood Draws

4:00 am-6:59 am 38.9%
7:00 am-11:59 am20.7%
12:00 pm-11:59 pm28.2%
12:00 am-3:59 am12.2%
Source: Caraballo et al. JAMA. 2023;329(3):255-257.

The relatively high proportion of early morning blood draws remained high during the study period.

Stress Linked to Sleep Deprivation

“Patients who were recently hospitalized experience a period of generalized risk for myriad adverse health events, a condition named posthospital syndrome,” said coauthor César Caraballo-Cordovez, MD, a postdoctoral associate at CORE. “The stress that patients experience during the hospitalization — including stress from sleep deprivation — is a key contributor to this period of increased risk.”

“We need to redesign our process to protect patients’ sleep, but major changes in our practice must be informed by solid studies that demonstrate the efficacy of strategies to do so without untoward effects,” added Dr Krumholz.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Caraballo C, Mahajan S, Murugiah K, et al. Timing of blood draws among patients hospitalized in a large academic medical center. JAMA. 2023;329(3):255-257. doi:10.1001/jama.2022.21509

This article originally appeared on Clinical Advisor