Respondent Characteristics
Of the 3000 invited physicians, 454 were excluded as undeliverable or ineligible (ie, retired, deceased, or no longer practicing medicine); of 2546 who were presumed to receive surveys, 890 physicians returned surveys (511 [57.4%] were male, and the mean [SD] years since graduation was 26.0 [11.7]), giving a response rate of 35.0% (890 of 2546) (