Plastic surgery audit codes: are the results reproducible?

The effective coding of data to produce a medical audit relies on agreement between the coders. This study was designed to assess whether coders can agree on codes for diagnosis and operations in a plastic surgery unit. Information from 50 patients was presented to a panel of six coders who were required to code the data using the International Classification of Diseases (ICD-9) and the Office of Population Census Studies (OPCS-4) systems. The results show that agreement between all the panellists occurred in only 32 out of 50 patients for one diagnostic code and 30 out of 50 for one operation code. When a patient had more than one diagnosis or operation, agreement was very much worse. Expert coders produced better results than the medical coders. The results are discussed with reference to other coding systems.