Duplicate patient records--implication for missed laboratory results.

Introduction: Although duplicate records are a potential patient safety hazard, the actual clinical harm associated with these records has never been studied. We hypothesized that duplicate records will be associated with missed abnormal laboratory results.

Methods: A retrospective, matched, cohort study of 904 events of abnormal laboratory result (HgbA1c, TSH, Vitamin B(12), LDL). We compared the rates of missed laboratory results between patients with duplicate and non-duplicate records from the ambulatory clinics. Cases were matched according to test and ordering physician.

Results: Duplicate records were associated with a higher rate of missed laboratory results (OR=1.44, 95% CI 1.1-1.9). Other factors associated with missed lab results were tests performed as screening (OR=2.22, 95% CI 1.4-3.4), and older age (OR=1.15 for every decade, 95% CI 1.01-1.2). In most cases test results were reported into the main patient record.

Discussion: Duplicate records were associated with a higher risk of missing important laboratory results.