Discordance between physicians and coders in assignment of diagnoses.

Objective: To measure concordance between physicians and medical record coders in their assignment of diagnoses.
Design: Prospective cohort series.
Setting: Five hundred and fifty-bed, tertiary-care, university teaching hospital. Study participants. In-patients who were discharged from either the Cardiac Sciences Program (n=125), the Renal Program (n=43), or the HIV-AIDS Program (n=25) during the period May 18-July 1, 1995.
Interventions: None.
Main Outcome Measures: Physicians and coders assigned diagnoses for individual in-patients based on their independent interpretations of the patient chart and discharge summary sheet. All assigned diagnoses were coded using the ICD-9-CM classification system. Concordance was measured for the most responsible diagnosis and for all assigned diagnoses. Difference in calculated resource intensity weights based on physicians' and coders' assignment of diagnoses was also calculated.
Results: Concordance rates for the most responsible diagnosis in each program were: Cardiac Sciences [27%; 95% confidence interval (CI)=20-36%], Renal Program (35%; 95% CI=21-53%), and HIV-AIDS Program (20%; 95% CI, 6-41%). Concordance rates for all diagnoses per chart were similar: Cardiac Sciences (20%; 95% CI, 14-25%), Renal Program (25%; 95% CI, 20-33%), and HIV-AIDS Program (29%; 95% CI, 25-44%). Resource intensity weights assigned by coders for the Cardiac Sciences and HIV-AIDS Program were significantly higher than those assigned by the physicians.