Validating billing data for RBC transfusions: a brief report

BACKGROUND: Administrative data are used often for research, but without va lidation of their accuracy. The validity of the billing for blood transfusi on was assessed in one tertiary-care hospital. MATERIALS AND METHODS: Patient discharge data were retrieved from a databas e containing demographics, diagnoses, and charges. There was random selecti on of 358 patients who were billed for RBC transfusion and 358 who were not . within a 2-month period. The blood bank's transfusion records were review ed. Sensitivity was defined as the proportion of transfused patients who we re billed, and specificity as the proportion of nontransfused patients who were not billed. Patient characteristics were compared by using Wilcoxon's rank sum test and the chi-square test. RESULTS: Sixty-one transfused patients were not billed for the transfusion. No patient was billed without transfusion, Thus, the sensitivity and speci ficity were 83 percent (95% CI, 79-87%) and 100 percent, respectively. Nine patients who were not issued RBCs were appropriately not billed for RBCs, although the billing record suggests they had a procedure involving transfu sion. These patients were called true-negative. The patients not billed wer e older (58 years vs. 55 years; p = 0.046) and less likely to have commerci al insurance (5% vs. 15%: p = 0.035) than billed patients. CONCLUSIONS: The billing for RBC transfusion in one large institution is re assuringly valid. The specificity is excellent, and the sensitivity is high er than that seen in other studies of coding validity.