Real-Time Alerts Reduce Unnecessary Blood Testing

(Agency for Healthcare Research and Quality)

An electronic message sent to physicians the moment they ordered a blood test for elderly patients reduced unnecessary use of a test that is often false-positive. Physicians received the alert in Kaiser Permanente’s electronic health record when ordering a D-dimer test for patients aged 65 and older.

The D-dimer test, combined with a clinical risking algorithm, can help diagnose deep vein thromboses, which are blood clots in veins. The test is also used to diagnose pulmonary embolisms, which are blood clots in the lungs. Kaiser Permanente says the risk of developing a blood clot in the venous circulation increases with age, yet the overall accuracy of the D-dimer test worsens as patients get older, and is only 35 percent for patients 65 years of age and over. This can result in numerous false-positives and additional, unnecessary testing.

The randomized trial of 223,877 patient visits for patients 65 years of age and over, and 564,264 patient visits for patients under 65 years of age, was conducted in eight Kaiser Permanente primary care clinics in Colorado, each with at least 3,000 patients aged 65 years or older. When doctors ordered the D-dimer test they immediately received an alert that explained the inaccuracy of the test for this age group and suggested using a radiological test as appropriate.

As a result, the rate of D-dimer tests for patients over 65 decreased significantly, from 5.02 to 1.52 per 1,000 patient visits, a relative reduction of D-dimer orders of nearly 70 percent. This decrease was maintained throughout the study period and the result was similar when the control group later received the alert.

The results will be published in the November issue of American Journal of Managed Care.

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