PHILADELPHIA -- Cutting the grueling work hours of doctors-in-training had little effect on reducing patient deaths, according to two large studies.
Death rates dropped in one group of patients in veterans' hospitals but not in three other groups, the researchers reported.
The results come from what the authors describe as the largest and most comprehensive national look at work-hour restrictions, which were implemented four years ago in an effort to reduce medical errors by tired physicians.
"We were a little surprised," said Dr. Kevin Volpp, the studies' lead author and a physician at the Philadelphia Veterans Affairs Medical Center. "We thought that mortality outcomes would improve more consistently."
The studies appear today's Journal of the American Medical Association.
The new work-hour rules limit doctors-in-training to 80-hour weeks. Critics of the restrictions feared they would hurt continuity of care for patients and create a shift-work mentality among doctors. Others supported the limits, saying they might lead to fewer deaths from medical mistakes.
Before the rules, medical residents often worked 100-hour weeks, with some shifts lasting 36 hours straight. Although the new limits are still roughly double what other full-time jobs require, long hours for doctors-in-training are seen as a traditional trial-by-fire approach that give them necessary, intensive experience.
The researchers looked at deaths that occurred within 30 days of hospital admission in the years before and after the rules went into effect in 2003. They compared death rates between hospitals with large number of residents and hospitals with few residents.