Study: Patients struggle to interpret lab results

Limited health literacy and numeracy skills prevent patients from successfully interpreting their online laboratory results, according to a study published in the Journal of Medical Internet Research.

More and more patients are accessing their online medical records and lab results outside of clinical consultations for both self-management of chronic conditions and for advance preparation for clinical visits. Researchers from the University of Michigan explored whether adults can identify laboratory blood test values outside reference ranges when presented in a format similar to some current patient portals implemented within EHR systems.

In the study, an online survey asked 1,817 adults ages 40-70—approximately half with diabetes—to imagine that they had Type 2 diabetes.

They were shown laboratory test results displayed in a standard tabular format, with randomized hemoglobin A1C values to be slightly (7.1 percent) or moderately (8.4 percent) outside the reference range and randomized other test results to be within or outside their reference ranges. The researchers assessed:

• whether respondents identified the hemoglobin A1C level as outside the reference range;
• how respondents rated glycemic control;
• whether they would call their doctor; and
• the numeracy and health literacy of the participants.

Both numeracy and health literacy were significant predictors of correctly identifying out-of-range values, according to the researchers. Only 38 percent of lower numeracy and literacy participants could correctly identify the hemoglobin A1C levels as outside the reference range.

Viewing test results with multiple deviations increased the probability of identifying hemoglobin A1C values as outside the reference range. Also, participants with diabetes were more likely to call a physician when the test results appeared abnormal.

“Limited health literacy and numeracy skills are significant barriers to basic use of laboratory test result data as currently presented in some EHR portals,” wrote Brian J. Zikmund-Fisher, PhD, Department of Health Behavior and Health Education, University of Michigan, and colleagues. “Alternate approaches appear necessary to make test results more meaningful.”

Read the full study here.