That's not really what that study says. The paper finds no difference between a "flexible" schedule and the standard duty-hour one.
Neither one of these schedules is really "reduced" compared to any sort of typical level: they're both ~80 hrs/week (and probably more).
From the paper:
"Programs assigned to the flexible-policy (intervention) group were required to adhere to ACGME duty-hour requirements of limiting work to 80 hours per week, 1 day off in 7 days, and on-call duty no more frequently than every third night, but they were granted a waiver by the ACGME to waive four duty-hour requirements (from the 2003 and 2011 reforms) concerning maximum shift length and minimum time off between shifts (to facilitate continuity of care) (Table 1)"
Neither one of these schedules is really "reduced" compared to any sort of typical level: they're both ~80 hrs/week (and probably more).
From the paper:
"Programs assigned to the flexible-policy (intervention) group were required to adhere to ACGME duty-hour requirements of limiting work to 80 hours per week, 1 day off in 7 days, and on-call duty no more frequently than every third night, but they were granted a waiver by the ACGME to waive four duty-hour requirements (from the 2003 and 2011 reforms) concerning maximum shift length and minimum time off between shifts (to facilitate continuity of care) (Table 1)"