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Lottery-based versus fixed incentives to increase clinicians' response to surveys.

OBJECTIVE
To compare the effects of lottery-based and fixed incentives on clinicians' response to surveys.


DATA SOURCES
Three randomized trials with fixed payments and actuarially equivalent lotteries.


STUDY DESIGN
Trial 1 compared a low-probability/high-payout lottery, a high-probability/low-payout lottery, and no incentive. Trial 2 compared a moderate-probability/moderate-payout lottery with an unconditional fixed payment (payment sent with questionnaire). Trial 3 compared a moderate-probability/moderate-payout lottery with a conditional fixed payment (payment promised following response).


PRINCIPAL FINDINGS
Neither the low-probability nor high-probability lotteries improved response compared with no incentive. Unconditional fixed payments produced significantly greater response than actuarially equivalent lotteries, but conditional fixed payments did not.


CONCLUSIONS
Lottery-based incentives do not improve clinicians' response rates compared with no incentives, and they are inferior to unconditional fixed payments.