The 50,000-number is derived from a study, released on Dec. 2, 2014, by the Agency for Healthcare Research and Quality, an arm of the Department of Health and Human Services. The study looked at the impact of the Partnership for Patients, a $460-million program funded by the health law which ties together 3,800 hospitals in 27 “health engagement” networks, with the goal of reducing ten categories of “patient harms,” such as adverse drug events, pressure ulcers and catheter-associated urinary tract infections. The networks work together to identify possible solutions to common problems and then circulate those ideas among the various hospitals, with the goal of reducing preventable hospital-acquired conditions (HACs) by 40 percent and 30-day hospital readmissions by 20 percent.

The study admits that “the precise causes of the decline in patient harm are not fully understood,” but notes that “the increase in safety has occurred during a period of concerted attention by hospitals throughout the country to reduce adverse events” though programs like the Partnership for Patients. So a key question is whether the impact is coincidental or the result of the ACA.

The study looked at the impact of the program from 2010 to 2013, so the 50,000 figure is a three-year number. But it is also an estimate, and we are always wary of estimates; the 2013 numbers are still considered interim. But the data set for the estimate is also rather rich.