Screening algorithms to assess the accuracy of present-on-admission coding.

Present-on-admission modifiers for International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes are rapidly becoming a standard coding requirement. Inaccurate coding of these modifiers can distort analyses of risk-adjusted outcomes and determinations of hospital reimbursement. A set of 12 screens for the plausibility of present-on-admission designations was developed and tested using New York State claims data for 2003, 2004, and 2005. Application of these screens uncovered numerous potential problems in coding with 39 percent of hospitals achieving a composite score higher than 90 percent and 36 percent of hospitals scoring 80 percent or less. Whether data quality control personnel adopt the screens employed in this study or develop similar sets of their own, the analytic approach used in this study provides a cost-effective method of assessing the quality of coding and the integrity of clinical performance reports based on enhanced claims data.