Low-Value Preoperative Tests Remain Commonplace

Routine testing before low-risk surgery has no known benefit, is overused and costly, and can lead to downstream care cascades, claims a new study.

Researchers at the University of Michigan (U-M; Ann Arbor, USA) conducted a study involving almost 40,000 patients who underwent low-risk, ambulatory surgical procedures in Michigan hospitals. The aim of the study was to examine the use of preoperative testing across diverse practice settings, assess inter-hospital and intra-hospital variations in testing, and identify determinants of testing in order to determine future targets for deimplementation strategies. The procedures selected included gall bladder removal, groin hernia repair, and cancerous breast tissue removal.


The results revealed that close to a third of the patients underwent two or more tests beforehand, and about 13% had three or more. The most common tests were a complete blood count, a basic metabolic panel, and an electrocardiogram (EEG). Patients who had a complete medical history and physical done during a visit that was separately billed were more likely to have had preoperative testing, as were those who were older or had co-morbidities. The data also revealed wide variations in testing between the 63 hospitals studied, but also within health systems. The study was published on May 17, 2021, in JAMA Internal Medicine.

“In the latter half of the 19th century, modern surgery was still in its infancy, anesthesia was new, and even minor surgeries were not routine. So researchers used tests to assess their patients' physical health and measure their risk of complications during operations,” said senior author Lesly Dossett, MD, PhD, of the division of surgical oncology. “There was probably a time when some of the testing did reduce adverse events. But now there have been so many advances in surgery, complication rates are so low that a lot of these tests are not necessarily helpful anymore.”

Common tests done before surgery include a chest X-rays, ECG, Urinalysis, a blood count that included white blood cells (WBCs), blood glucose, potassium, sodium, and other electrolytes, and coagulation studies (PT/PTT).

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