Coding of diagnoses, comorbidities, and complications of total hip arthroplasty.

International Classification of Diseases coding of patient charts is used by hospitals to allow for billing of patients. Coding information also is used for assessing physician effectiveness. The purpose of the current study was to examine hospital coding for patients having total hip arthroplasty. One hundred consecutive primary total hip replacements were done at one medical center by two orthopaedic surgeons. Patient charts were coded by hospital coders according to the Health Care Finance Administration guidelines. Subsequently, an orthopaedist-based team did a secondary review of these charts and the two sets of codes were compared. The diagnostic codes were similar between the two groups for 87% (174 of 200 codes) of the cases. Comorbidities generally were undercoded by the hospital coders who reported 2.9 comorbidities per patient, whereas the secondary review reported 3.7 comorbidities per patient. The hospital coders found a complication rate of 1.2 per patient, whereas the secondary review revealed a rate of 0.4 per patient. Based on the results of the current study, the authors conclude that it is important to ensure three issues regarding the standard of coding and quality control: (1) the qualifications of the coders; (2) an interaction between coders and healthcare professionals to check that coding is accurate and reproducible; and (3) communication among various health professionals (including the primary surgeon) and coders to determine what actually are appropriate diagnoses, comorbidities, and complications.