How Much Money Is Enough to Entice Physicians to Participate in Research Surveys? Findings from a Randomized Experiment (Preprint)

Abstract

Online surveys can be effective data collection instruments; however, participation is notoriously low, particularly among professionals such as physicians. Few studies have explored the impact of varying amounts of monetary incentives on survey completion.

We conducted a randomized study to assess how different incentive amounts influenced participation among neurologists in the United States.

We distributed a web-based survey using standardized email text to 21,753 individuals randomly divided into five equal groups (~4351 per group). In Phase 1 each group was assigned to receive either nothing or a gift card for $10, $20, $50, or $75, which was noted in the email subject and text. After four reminders, Phase 2 began and each remaining individual was offered a $75 gift card to complete the survey. We calculated and compared the proportions who completed the survey by Phase 1 arm, both before and after the incentive change. As a secondary outcome, we looked at survey participation as opposed to completion.

Overall, 879 (4.2%) recipients completed the survey; for Phase 1, the proportions increased as the incentive amount increased (1.1%, 1.8%, 2.1%, 2.5%, and 2.9%, for $0, $10, $20, $50, and $75, respectively, χ2 P<0.0001). In Phase 2, the survey completion rate for the former $0 arm increased to 3.0%. Those originally offered $10, $20, $50, and $75 who had not yet participated were less likely to participate compared with the former $0 arm (3.0%, 2.3%, 2.1%, 2.3%, and 1.9%, for $0, $10, $20, $50, and $75, respectively, χ2 P=0.027). For our secondary outcome of survey participation, a trend similar to that of survey completion was observed in Phase 1 (1.3%, 2.0%, 2.3%, 2.8%, and 3.3%, for $0, $10, $20, $50, and $75, respectively, χ2 P <0.0001), and Phase 2 (3.0%, 2.3%, 2.1%, 2.3%, and 2.2%, for $0, $10, $20, $50, and $75, respectively, χ2 P =0.097).

As expected monetary incentives can boost physician survey participation and completion, with a positive correlation between the amount offered and participation.