Too many routine preoperative tests performed before low-risk medical procedures

  • June 1, 2015

June 1, 2015  |  Download Release


Guidelines recommend limiting medical tests before low-risk surgeries, however electrocardiograms and chest x-rays are still frequently performed, according to a study by researchers at the Institute for Clinical Evaluative Sciences (ICES) and Women’s College Hospital.

Evidence indicates that for patients undergoing low-risk surgery, routine testing does not improve outcomes and can actually lead to surgical delays, patient anxiety and other issues. The Choosing Wisely campaign, which started in the United States and spread to Canada in April 2014, aims to reduce unnecessary low value care practices by changing physician and patient attitudes.

The researchers looked at ICES data on more than 1.5 million patients aged 18 and over who underwent more than two million procedures such as endoscopy, opthalmologic surgery and low-risk surgery including knee and hernia repair in 137 institutions in Ontario from April 1, 2008 to March 31, 2013. Despite guidelines that do not recommend routine cardiac screening before low-risk procedures, the researchers found that electrocardiograms (ECGs) were performed before about one-third of surgeries. Preoperative testing was performed more frequently in older patients, with ECGs conducted 18.3 times more often in people over age 65 than in patients aged 18 to 25.

“Our study shows that rates of preoperative testing before low-risk procedures are higher than expected, with significant variation at the regional and institutional level across hospitals,” said Dr. Sacha Bhatia, cardiologist at Women’s College Hospital and a scientist at ICES.

The researchers found a 30-fold difference in rates of preoperative procedures between institutions with the lowest rates of preoperative tests and those with the highest rates.

Previous studies have looked at older patients over age 65, whereas this study looked at all patients over the age of 18.

“Our results suggest that the major drivers of preoperative testing are older age, procedure type, concurrent preoperative consultation, and the institution at which the procedure is conducted. Interestingly, patient co-morbidities, particularly cardiac co-morbidities, were not major drivers of pre-operative testing,” adds Bhatia.

“Preoperative Testing Prior to Low-risk Surgical Procedures,” was published in the CMAJ.

Author block: Kyle R. Kirkham, Duminda N. Wijeysundera,  Ciara Pendrit,  Ryan Ng, Jack V. Tu  Andreas Laupacis, Michael J. Schull, Wendy Levinson and R. Sacha Bhatia.



About Women’s College Hospital 

For more than 100 years Women’s College Hospital (WCH) has been developing revolutionary advances in healthcare. Today, WCH is a world leader in the health of women and Canada’s leading, academic ambulatory hospital. A champion of health equity, WCH advocates for the health of all women from diverse cultures and backgrounds and ensures their needs are reflected in the care they receive. It focuses on delivering innovative solutions that address Canada’s most pressing issues related to population health, patient experience and system costs. The WCH Institute for Health System Solutions and Virtual Care (WIHV) is developing new, scalable models of care that deliver improved outcomes for patients and sustainable solutions for the health system as a whole. 

For more information about how WCH is transforming patient care and leading health system solutions, visit

Fully affiliated with

A member of