Hidden in Plain Sight: Overlooked Results and Other Errors in Evaluating Online Laboratory Results

People are increasingly accessing their own laboratory (lab) results online. However, Canadians may be expected to use different systems to access their results, depending upon where they are tested (e.g., community lab vs. hospital), and these results may be displayed differently. This study examined the extent to which participants without medical expertise (N = 25) made errors identifying lab results (i.e., missing or mis-identifying abnormal results) in a mock report. Six participants overlooked each of the flagged values, 20 participants missed an abnormal result that was not flagged, and 2 participants mis-identified a normal value as out of range. We describe potential causes of these errors and the implications for the design of consumer-facing lab results.