A Retrospective, Matched-Cohort Study Is Conducted to Examine the Effect

question 734

Multiple Choice

A retrospective, matched-cohort study is conducted to examine the effect of medical care provided by overnight physicians on the outcomes of their scheduled elective procedures performed during the day.  Patients undergoing 1 of 5 elective daytime procedures performed by a physician who worked overnight were matched to patients undergoing the same procedure by the same physician on a day when the physician did not work overnight.  The study outcome was a composite of patient death and complications.  The study reported that the risk of the composite outcome was higher in patients who underwent a daytime procedure performed by a physician who had worked overnight compared to patients who underwent a procedure performed by a physician who had not worked overnight (22% vs. 20%, p = 0.04) .  Based on these results, what is the approximate percentage of deaths and complications that can be attributed to the physician having worked overnight before the scheduled elective procedures during the day?

• A)1)1
• B)9)1
• C)22
• D)50