Adverse drug effects in hospitalized elderly: Data from the Healthcare Cost and Utilization Project

We aimed to analyze trends in hospital admissions due to adverse drug effects between the years 2000 to 2007 among the elderly using the National Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project. We identified the discharges with the principal and all listed diagnoses related to adverse drug effects and associated hospital charges using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes. Between 2000 and 2007, 321,057 patients over 65 years were discharged with a principal diagnosis related to an adverse drug effect. Hospital charges were $5,329,276,300 or $666,159,537 annual cost. The number of discharges and total hospital charges did not change over the examined years, while mean charge per discharge increased on average by $1064 ± 384 per year. Total hospital charges for drug-induced gastritis with hemorrhage increased the most by $11,206,555 per year among those 66-84 years old and by $8,646,456 per year among those older than 85 years. During 2007, 791,931 elderly had adverse treatment effects among all listed diagnoses with hospital charges of $937,795,690. Effective drug management interventions are needed to improve safety of treatments in the elderly.