A randomized trial of opinion leader endorsement in a survey of orthopaedic surgeons: effect on primary response rates

Background Opinion leaders have been shown to have significant influence on the practice of health professionals and patient outcomes. Methods Using focus groups, key informants, and sampling to redundancy techniques, we developed a questionnaire of surgeons' preferences in the treatment of tibial shaft fractures. Twenty-two well-respected and widely known orthopaedic traumatologists endorsed the questionnaire. We randomized 395 surgeon members of the Orthopaedic Trauma Association to receive either a questionnaire that included a letter informing them of the opinion leaders' endorsement, or a questionnaire without the endorsement. Results Surgeons who received the letter of endorsement had a significantly lower response rate at 2, 4, and 8 weeks. The absolute difference in response rates was 7.8% (4.6% versus 12.4%, P<0.05) at 2 weeks, 13.1% at 4 weeks (28.6% versus 41.7% P<0.02), and 12.3% at 8 weeks (47.5% versus 59.8% P=0.02). Conclusions The addition of a letter listing expert surgeons who endorse the survey lead to significantly lower primary response rates. Those interested in influencing physician responses cannot always assume a positive effect from endorsement by opinion leaders.