In 1990, he and Professor Tversky published a paper in The New England Journal of Medicine showing that when physicians make a medical decision for a single hypothetical patient, they favor more expensive treatments than when making a decision for a group of hypothetical patients with similar symptoms. And in 1996 the two scientists found that increased arthritis pain had nothing to do with the weather. They attributed the misperception to the human tendency to look for patterns even where none may exist.

Dr. Redelmeier credits Professor Tversky, who died in 1996, with shaping his own approach to research in the medical realm. “He provided me with a language and a logic for tackling issues that seemed to be around me all the time, but weren’t so apparent to other people,” he said.

Dr. Redelmeier isn’t one to forget about his past research. With the Academy Award study, for instance, he regularly updates the database.

“It’s important for him to know this wasn’t some statistical blip we happened to stumble across,” said Dr. Sheldon Singh, a cardiologist at Sunnybrook Hospital and assistant professor of medicine at the University of Toronto who co-wrote the Academy Awards paper. And in a paper coming out in the September issue of Chance, a statistics journal, Dr. Redelmeier and Professor Tibshirani show that on Election Day 2008, more fatalities occurred than on two control days, the Tuesdays before and after the election. This paper is a follow-up to an earlier one published in The Journal of the American Medical Association.

“Part of the satisfaction for Don is knowing the results stand the test of time,” Dr. Singh said.

Dr. Redelmeier’s unusual approach goes hand in hand with some pronounced personality quirks. His e-mails, which are legendary among their recipients, are written as lists, with a number assigned to each thought. Dr. Redelmeier does this, he said, in order to focus on the content of a message rather than get distracted by grammar, punctuation and syntax.

“I remember the first time I got one, I was a little offended,” Dr. Singh said. “I’d never gotten an e-mail not written in a paragraphed format. Yet he addressed everything I needed to know.”

Dr. Redelmeier takes the results of his research seriously. He rides his bike to work, and when he does drive, he resists “small temptations to change lanes.”