People who have late-day prostate and kidney surgeries fare just as well as those who have their procedures earlier in the day, according to a new study. Previous research has hinted that morning procedures—including colonoscopies and surgeries to insert a stent—might be safer or more successful than those done later in the day (for example, see Reuters Health report of June 17, 2010). Surveys have also shown many surgeons get physically and mentally tired—but it hasn't been clear whether this results in worse performance as the day goes on. "We really didn't find any significant differences one way or another (between early and late surgeries), which is reassuring," said Dr. Yair Lotan, the senior author of the new study from the University of Texas Southwestern Medical Center at Dallas.