EHR Medication Lists Inaccurate, Incomplete, Blood Tests Show

Marcia Frellick

November 05, 2018

Researchers who checked patients' blood samples for medication concentration found that more than half were taking prescription and/or over-the-counter drugs not listed in their electronic health record (EHR), indicating potential threats to patient safety.

Additionally, more than half of the drugs that triggered drug–drug interaction alerts in the study involved medications not listed in EHRs.

Jeffrey J. Sutherland, PhD, of Precera Bioscience in Franklin, Tennessee, and colleagues published the results of their study online November 2 in JAMA Network Open.

Single Test Detects 263 Medications

The researchers developed a liquid chromatography–tandem mass spectrometry assay that accurately measures 263 prescribed and over-the-counter medications in a single blood sample.

To assess the accuracy of the EHR medication lists, they collected blood samples from patients at three medical groups, Cleveland Clinic in Ohio, Vanderbilt University Medical Center, in Nashville, Tennessee, and the Associates in Gastroenterology, in Nashville.

Researchers analyzed samples in a cross-sectional study of 1346 patients in three care settings: the residuals cohort, in which residual serum from 1000 randomly selected samples were sent for routine clinical chemistry testing; the gastroenterology care cohort, which included 50 prospectively enrolled patients in a gastroenterology clinic who were prescribed more than five medications; and an emergency department (ED) cohort, in which a convenience group of 296 patients with hypertension sought care in an ED.

Of those 1346 samples, 78% to 100% of medications were detected as prescribed in the EHR medication list.

However, in 63% of patients (848 of 1346) the EHR medication list and the detected medications did not match.

In the residuals cohort, only 435 patients (43.5%) had no discrepancy between the EHR and detected medications. In the gastroenterology care group, 22 patients (44%) had no discrepancy, and in the ED group, 41 patients (13.9%) had no discrepancy.

Researchers found that opioids and diazepam were the most common medications detected without evidence of prescription.

Medications used to treat cardiovascular and other chronic diseases were also often found in patients whose EHR didn't list them, according to the authors.

"More important," they write, "a disproportionate number of potentially interacting medications were noted among patients without evidence of a prescription, suggesting that healthcare professionals may be prescribing and making clinical care decisions with incomplete information."

"As an example, 429 of 1678 (25.6%) medications detected in patients in the ED care cohort were not listed in the prescription record; however, 131 of 265 (49.4%) predicted drug–drug interactions came from these medications."

In a combined analysis of all three cohorts, the researchers found that 318 of 601 (52.9%) major or severe drug–drug interactions involved medications that were detected but not prescribed.

Monika Safford, MD, a clinician investigator and chief of the Division of General Internal Medicine at Weill Cornell Medicine and New York-Presbyterian in New York City, told Medscape Medical News that she was not familiar with the blood analysis the researchers used. Without evidence of validation studies, she said, "it is not clear how reliable this method is in detecting drugs. The results suggest that the sample was highly adherent to medications, but it would be important to understand the limitations of the assay in interpreting the results of the study."

She added that it's unclear whether such a test would be worth the cost.

Checking blood for adherence, she notes, assumes that just asking patients what they're taking, and what they should be taking but aren't, is not good enough.

"There are a lot of studies that just ask, and when people admit they don't always take the drugs, the studies suggest they are telling the truth. This test is likely to cost something, so it is not clear what it adds to what we already know," she said.

Adherence to One Drug Predicts Adherence to Several

The researchers also found, surprisingly, that adherence to one medication was associated with adherence to other medications (odds ratio for a 1% increase in adherence to other drugs, 1.03; 95% CI, 1.02 - 1.03; P < .001).

That led the authors to conclude, "The best determinant of whether patients take their medication is whether they take concomitant medications, demonstrating that behavior is one important parameter underlying variability in response to treatment."

Safford said that finding was not surprising to her. "Numerous studies show that as people get sicker, their medication adherence improves," she noted. And the more medications someone takes, the sicker they are likely to be.

The authors call for comprehensive medication monitoring to improve adherence and reconcile medical records and to provide better information for prescribers choosing medications.

Sutherland and coauthors have reported receiving salaries from and holding shares in Precera Bioscience. The coauthors have received support from the 2017 Heart Failure Society of America/Emergency Medicine Foundation Acute Heart Failure Young Investigator Award, funded by Novartis and National Institutes of Health. The portions of the clinical research performed at Cleveland Clinic and Associates in Gastroenterology were funded by Precera Bioscience. The portion of the clinical research conducted at Vanderbilt University Medical Center was funded in part by Clinical and Translational Science Awards.

JAMA Network Open. Published online November 2, 2018. Full text

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