Will donations to their learned college increase surgeons' participation in surveys? A randomized trial

Effective strategies to maximize response rates to self-administered surveys of clinicians are crucial to minimize response bias. Offers of charitable donations have been assessed for their potential to promote participation of community samples but not in the context of medical specialist samples. We randomized all Australian colorectal surgeons (n = 219) to whom we mailed a survey about clinical practice guidelines to receive either a standard covering letter or one promising a donation to their peak professional organization upon our receipt of their completed survey. Contrary to expectations, surgeons advised that their participation would secure a donation to their college were significantly less likely to return their questionnaire (84.3%, 95% CI 76.0-90.5%) than those receiving a standard letter (93.7%, 95% CI 87.4-97.4%). They also were more tardy in their response (Hazard Ratio = 0.75, 95% CI 0.57-1.00) (P = 0.047). In this context, offering donations to surgeons was counterproductive in enhancing response rates.