Direct-to-Consumer Laboratory Panels: Downstream Testing Generated by Unsolicited Abnormal Results

Abstract

Direct-to-consumer laboratory testing panels, purchased without clinician involvement and often covering dozens of analytes at
once, generate abnormal results at a rate driven substantially by the statistical consequence of testing many analytes
simultaneously rather than by underlying disease prevalence, and these unsolicited abnormal results are frequently brought to
primary care for interpretation and follow-up. We reviewed primary care consultation and downstream testing records for 412
patients presenting with a direct-to-consumer panel result over an eighteen-month period across nine primary care practices. At
least one abnormal result was present in 78% of panels reviewed (median 34 analytes tested), and downstream confirmatory or
follow-up testing was initiated for 61% of presentations, of which 84% ultimately identified no clinically significant abnormality.
We estimate the downstream testing burden this generates and discuss what primary care and laboratory services can do to
manage a pattern that direct-to-consumer testing appears set to increase rather than reduce.