Hamilton Health Sciences finds better way to interpret blood tests:Most study subjects were HHS or St. Joe's hospital patients

A study led by Hamilton researchers has found a new way to interpret blood test results in patients who are being checked for a pulmonary embolism or blood clots in their lungs.

This new approach applies to D-dimer blood tests, which are used by physicians to rule out the presence of a blood clot.

Researchers found that a higher-than-usual D-dimer level can be considered a negative result if the physician has assessed the patient as having a low probability of having a pulmonary embolism.

The study team says the findings are important, as they mean a lot fewer patients need a computerized tomography (CT) scan, which results in patients avoiding radiation exposure and spending less time in the emergency department.

In addition, the health system also benefits as it frees up CT scans for other patients — and it improves the ability to move patients more quickly through the emergency department.

The study results have been published in the New England Journal of Medicine.

A total of 2,017 patients aged 18 and older were enrolled and evaluated in the study, of which seven per cent had a pulmonary embolism on initial diagnostic testing. The average age of the patients was 52 years, and 66 per cent were female.

Of the patients in the study, 73 per cent, or 1,474, were enrolled at Hamilton Health Sciences or St. Joseph’s Healthcare Hamilton.

These patients, and those at other university-based clinical centres in Canada, were tested from December 2015 through May 2018 and assessed 90 days later.

The study was organized by the Ontario Clinical Oncology Group of McMaster and Hamilton Health Sciences, and is funded by the Canadian Institutes of Health Research and endorsed by the Canadian Venous Thromboembolism Clinical Trials and Outcomes Research.