With Carole R. Gresenz, Scott Laughery, and Amalia R. Miller
US government investments in health information technology (IT) reflect the significant promise of digitization for improving quality and efficiency in health care. Previous studies of the impact of health IT have focused on the hospital setting, despite the fact that most care is delivered in ambulatory settings. This paper addresses the research omission by studying the effects of healthcare IT on ambulatory care, which we measure using the rate of hospital admissions for conditions identified as sensitive to ambulatory care quality in data drawn from Medicare and the Healthcare Cost and Utilization Project. Results from difference-in-differences models that control for location and time fixed effects, as well as observable factors related to healthcare quality and population demographics, indicate that increased ambulatory IT adoption lowers local area ambulatory care sensitive (ACS) hospitalizations, suggesting quality improvements. The magnitudes imply that a 45% increase in ambulatory IT adoption in a county (the average increase over our sample period 2003-2012) lowers the ACS admission rate in that county by about 1.6%.