BILLING FOR PHYSICIAN SERVICES - A COMPARISON OF ACTUAL BILLING WITH CPT CODES ASSIGNED BY DIRECT OBSERVATION

BACKGROUND. Little is known about the accuracy of family physicians' u se of the Current Procedural Terminology (CPT) coding scheme for offic e visits, despite increased administrative oversight of Medicare billi ng practices. In addition, the patient and visit characteristics that are associated with over- and undercoding are not well understood. MET HODS. This study compared coding for evaluation and management (E&M) s ervices billed for 3791 visits to 138 family physicians with the codes assigned by trained research nurses using direct observation. We calc ulated the degree to which the codes for E&M were concordant with the observer-assigned codes. Analysis of variance and logistic regression were used to examine the association of visit and patient characterist ics with discordance between billed and observer-assigned CPT codes. R ESULTS. Billing codes were concordant for 55% of encounters. Discordan ce was evenly distributed between under- and overcoding. Concordance o f billed and observed codes was greatest for patients with indemnity i nsurance. Undercoding increased with longer visit length and a smaller percentage of the visit spent planning treatment. Overcoding was more common during visits with a greater percentage of time spent chatting , planning treatment, and delivering preventive services. CONCLUSIONS. Family physicians are generally accurate in their billing procedures. The findings on patient and visit characteristics associated with ove r- or undercoding may be used by practicing clinicians to enhance the accuracy of their coding and billing procedures.