Most daily blood draws were collected during traditional sleep hours
At one U.S. teaching hospital, about 39% of blood draws for adult patients were collected between 4 and 6:59 a.m. from November 2016 through October 2019, although the timing shifted to slightly later during that period.
Nearly 4 in 10 daily blood draws at one hospital were collected in the early morning during traditional sleep hours, a recent study found.
Researchers looked at electronic health records to evaluate all blood draw events for adult patients hospitalized within both campuses of a large U.S. teaching hospital from November 2016 through October 2019. They excluded blood draws performed in the ED, critical care units, and step-down units, as well as those performed during the first 24 hours after admission (to avoid nonroutine blood draws obtained during the initial evaluation). The hospital's primary clinical teams' blood draw orders specified the exact desired timing of collection, set to 6 a.m. as the default. There were no hospital policies that specifically modified timing of blood draws during the study period. The researchers assessed differences in timing of blood draws over the study period, particularly the proportion of samples collected between 4 and 6:59 a.m. (early morning). Results were published as a research letter Jan. 17 by JAMA.
The final study sample included about 5.7 million blood draws from 79,347 patients. Most (38.9%) samples were drawn between 4 and 6:59 a.m. (8.9% from 4 to 4:59 a.m., 16.5% from 5 to 5:59 a.m., and 13.5% from 6 to 6:59 a.m.). Outside the early morning hours, 20.7% of blood draws were performed between 7 and 11:59 a.m., 28.2% between noon and 11:59 p.m., and 12.2% between midnight and 3:59 a.m. During the study period, the monthly proportion of early-morning blood draws increased from 36.9% to 41.4% (change, 4.5 percentage points [95% CI, 4.1 to 4.9]; P<0.001). During the early-morning hours, the proportion of samples drawn between 4 and 4:59 a.m. decreased from 9.5% to 7.7% (change, −1.8 percentage points [95% CI, −2.1 to −1.6]), the proportion drawn between 5 and 5:59 a.m. increased from 14.6% to 18.8% [change, 4.2 percentage points [95% CI, 3.9 to 4.5]), and the proportion drawn between 6 and 6:59 a.m. increased from 12.8% to 14.9% (change, 2.1 percentage points [95% CI, 1.8 to 2.4]; P<0.001 for all comparisons).
The study was limited by its single-center design, the authors noted. They added that they could not exclude urgent early-morning blood draws performed on medical and surgical floors from their analysis.
“Early morning blood draws may be necessary to assess patients' health status during morning rounds and occasionally to inform discharge decisions, but patient-centered care should consider strategies to limit nonurgent tests during sleep hours,” they wrote. “Studies are needed to assess if improving sleep by limiting early morning blood draws and other interruptions could improve patient outcomes without untoward effects on quality of care.”
