The study aimed to estimate the number of healthcare-associated infections (HAIs) and associated deaths in U.S. hospitals in 2002. Using a multi-step approach and data from the National Nosocomial Infections Surveillance (NNIS) system, the National Hospital Discharge Survey (NHDS), and the American Hospital Association Survey, the authors estimated that there were approximately 1.7 million HAIs and 98,987 deaths associated with HAIs in U.S. hospitals in 2002. The majority of HAIs occurred among adults and children outside of ICUs, with pneumonia and bloodstream infections being the leading causes of death. The study highlights the significant impact of HAIs on morbidity and mortality and underscores the need for improved prevention and surveillance efforts. However, the estimates have limitations, including the use of older infection rates and the potential underreporting of surgical site infections.The study aimed to estimate the number of healthcare-associated infections (HAIs) and associated deaths in U.S. hospitals in 2002. Using a multi-step approach and data from the National Nosocomial Infections Surveillance (NNIS) system, the National Hospital Discharge Survey (NHDS), and the American Hospital Association Survey, the authors estimated that there were approximately 1.7 million HAIs and 98,987 deaths associated with HAIs in U.S. hospitals in 2002. The majority of HAIs occurred among adults and children outside of ICUs, with pneumonia and bloodstream infections being the leading causes of death. The study highlights the significant impact of HAIs on morbidity and mortality and underscores the need for improved prevention and surveillance efforts. However, the estimates have limitations, including the use of older infection rates and the potential underreporting of surgical site infections.