Protected sleep time allows medical trainees to sleep more

In the last few years, the hours worked by medical interns and residents has come under scrutiny. Regulations have been put in place to limit the number of hours worked in an attempt to reduce patient errors. Here is an article about a study showing that if you give medical trainees 5 hour protected time to sleep while on call, they will sleep an extra hour on average. However, the researchers did not measure medical errors, so it's not clear if that extra hour of sleep made any significant difference.