Identifying hospital-wide harm: a set of ICD-9-CM-coded conditions associated with increased cost, length of stay, and risk of mortality

Abstract

This study identifies an expanded set of hospital-acquired conditions (HACs), using the Present-On-Admission (POA) indicator and secondary diagnoses present on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-coded discharge abstracts and evaluates their association with mortality, length of stay (LOS), and cost. A sample of 500 000 de-identified ICD-9-CM-coded discharge abstracts was randomly drawn from a data set of 11 million. A total of 138 secondary condition clusters were identified as potential inpatient complications (PICs). Regression modeling was used to determine marginal association of each PIC with mortality, LOS, and cost. In all, 16% of hospitalized patients developed 1 or more of these conditions while in the hospital compared with less than 1% of inpatients experiencing HACs defined by the Centers for Medicare and Medicaid Services. Also, 74 PICs were associated with seriously higher mortality rates (5 excess deaths per 1000), significantly LOS (0.4 extra days per discharge), and significantly higher costs (an extra $1000 per discharge).

Keywords: complications; harm; hospital-acquired conditions; present on admission indicator; safety.