Accuracy of CPT Evaluation and Management Coding

Abstract & commentary

Synopsis: The error rate for physician coding of patient visits is substantial and appears to occur more frequently for new patient visits than for established patient visits. The complexity of the CPT coding guidelines and a lack of physician training in CPT coding probably accounts for the error rate.

Source: King MS, et al. J Am Board Fam Pract. 2001;14: 184-192.

Current procedural terminology (cpt) coding is designed to reflect the resources used when providing care. Clinicians use CPT codes to bill Medicare and other payers for their services. Proper coding has important legal and financial implications. Clearly the level of coding translates into practice reimbursement. Also, accurate coding documents the level of services and helps protect physicians from the legal ramifications of a Medicare audit.

This study examined how accurately a sample of family physicians code outpatient visits. A group of 600 randomly selected family physician members of the Illinois Academy of Family Physicians were sent the progress notes of 6 patients to code. The 6 cases represented both new and established visits and different levels of services. The physicians were asked to code the level of service for each of the visits. In addition, they completed a brief demographic survey to elicit coding practices and characteristics that might be associated with coding ability. The physicians’ coding was then compared to a gold standard which represented the consensus code of 5 expert billing coders.

The response rate to the survey was 42%. For established patient visits, physicians agreed with the experts’ consensus codes in 52% of the cases, overcoded in 16% of the cases, and undercoded in 33% of the cases. For new patients, physicians agree in only 17% of the cases, with overcoding in 82% of the cases and undercoding in 1% of the cases. No statistically significant relationships were found between physician accuracy in coding and variables such as years in practice, coding training, patient care time, and charges for office visits.

Comment by martin lipsky, md

King and colleagues conclude that physicians have difficulty in accurately applying the current CPT guidelines. Given the recent concern regarding coding fraud, the study’s format removed any financial incentives for coding, strongly supporting natural error rather than an attempt to defraud as a cause for coding errors. Although this study was done with family physicians, there is no reason to believe that internists would also experience a similar error rate. Certainly when I discuss coding with my internal medicine colleagues they relate the same frustrations and uncertainty that I do about CPT coding. However, future studies looking at coding across specialties would be interesting.

This study also notes that the pattern of error differs between new and established patients. The physicians tended to overcode new visits more than old visits. It is possible that many physicians did not recognize that new patient visits require more documentation to establish a higher service level. Another possiblity is the sense physicians have that new patients require more effort and their coding levels could reflect this assumption.

Although no financial analysis was done, it appears that overcoding was balanced by undercoding suggesting that the overall financial impact of coding errors was neutral. For many of us faced with coding our visits, this study supports the contention that there might be a simpler set of guidelines in the future. To their credit, the CMS (the new acronym for HCFA) is trying to develop their guidelines. In the meantime, this study provides evidence that a certain amount of error in coding is inherent with the current guidelines.