Retrospective analyses of routine preoperative blood testing in a tertiary eye hospital: could Choosing Wisely work...

To explore the possibility of implementing Choosing Wisely on ocular patients in China by investigating the prevalence of abnormalities in routine preoperative blood tests (RPBTs) and its turnaround time (TAT).

Data from 102 542 ocular patients between January 2016 and December 2018, at Zhongshan Ophthalmic Center, were pooled from the laboratory information system. The test results were divided into normal and abnormal, including critical values. Ocular diseases were stratified into 11 subtypes based on the primary diagnosis. The TAT of 243 350 blood tests from January 2017 to December 2018 was categorised into transportation time and intralaboratory time.

RPBT was grouped into complete blood count (CBC), blood biochemistry (BBC), blood coagulation (BCG) and blood-borne pathogens (BBP), completed for 97.22%, 87.66%, 94.41% and 95.35% of the recruited patients (male, 52 549 (51.25%); median(IQR) age, 54 (29-67) years), respectively. Stratified by the test items, 9.19% (95% CI 9.07% to 9.31%) were abnormal results, and 0.020% (95% CI 0.019% to 0.022%) were critical; most abnormalities were on the CBC, while glucose was the most common critical item. Classified by the patients' primary diagnosis, 76.97% (95% CI 76.71% to 77.23%) had at least one abnormal result, and 0.28% (95% CI 0.25% to 0.32%) were critical; abnormal findings were reported in 45.29% (95% CI 44.98% to 45.60%), 54.97% (95% CI 54.65% to 55.30%), 30.29% (95% CI 30.00% to 30.58%) and 11.32% (95% CI 11.12% to 11.52%) for the CBC, BBC, BCG and BBP tests, respectively. The median transportation time and intralaboratory TAT of the samples were 12 min and 78 min respectively.

Blood abnormalities are common in ocular patients. With acceptable timelines, RPBT is still indispensable in China for patient safety.