Limiting work shifts to 16 hours generally makes first-year medical residents more satisfied with their training and work-life balance, but their training directors more dissatisfied with curtailed educational opportunities, according to a study published online this week in the New England Journal of Medicine. The Accreditation Council for Graduate Medical Education in 2011 limited first-year residents, known as interns, to 16-hour shifts and more senior residents to 28-hour shifts. The study surveyed and tracked the activities of thousands of first-year residents in 63 internal medicine training programs randomly assigned to either the standard 2011 duty-hour policies or more flexible policies. Observers found that the percent of time spent on direct patient care and education were statistically the same in both program types. Scores on a national in-training exam that helps gauge medical knowledge in the second year of residency also showed no difference between interns in the two arms of the study. The ongoing study, funded by the ACGME and National Heart, Lung and Blood Institute and led by the Perelman School of Medicine at the University of Pennsylvania in collaboration with The Johns Hopkins University, also will evaluate the effect of alternative duty-hour policies on patient safety and intern sleep and alertness.