Clinical impact associated with corrected results in clinical microbiology testing.

We developed a strategy to determine the clinical impact associated with errors in clinical microbiology testing. Over a 9-month period, we used a sequential three-stage method to prospectively evaluate 480 consecutive corrected microbiology laboratory reports. The three stages were physician review of the corrected report, medical record review, and interview with the clinician(s) taking care of the patient. Of the 480 corrected reports, 301 (62.7%) were ruled out for significant clinical impact by physician review and an additional 25 cases (5.2%) were ruled out for clinical impact by medical record review. This left 154 cases (32.1%) that required clinician interview to determine clinical impact. The clinician interview revealed that 32 (6.7%) of the corrected reports were associated with adverse clinical impact. Of these 32 cases, 19 (59.4%) involved delayed therapy, 8 (25.0%) involved unnecessary therapy, 8 (25.0%) were associated with inappropriate therapy, and 4 (12.5%) were associated with an increased level of care. The laboratory was entirely responsible for the error in 28 (87.5%) of the 32 cases and partially responsible in the other 4 cases (12.5%). Twenty-six (81.3%) of the 32 cases involved potentially preventable analytic errors that were due to lack of knowledge (cognitive error). In summary, we used evaluation of corrected reports to identify laboratory errors with adverse clinical impact, and most of the errors were amenable to laboratory-based interventions. Our method has the potential to be implemented in other laboratory settings to identify and characterize errors that impact patient safety.