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The effects of cash and lottery incentives on mailed surveys to physicians: a randomized trial

Gabriel M Leung1, Lai Ming Ho, Moon Fai Chan

  • 1Department of Community Medicine, Faculty of Medicine, University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong. gmleung@hku.hk

Journal of Clinical Epidemiology
|October 18, 2002
PubMed

Insights

Offering incentives significantly boosts mailed survey response rates, particularly for physicians. Cash incentives proved more effective than lottery incentives, with a $20 cash reward being the most cost-effective option.

Area of Science:

  • Epidemiology
  • Health Services Research

Background:

  • Low response rates in mailed surveys, especially among physicians, pose a significant challenge.
  • Effective strategies are needed to improve participation in health research.

Purpose of the Study:

  • To evaluate the impact of cash and lottery incentives on mailed survey response rates.
  • To determine the most cost-effective incentive strategy for improving survey participation.

Main Methods:

  • A randomized trial involving 4,850 subjects receiving a mailed survey.
  • Interventions included no incentive, varying levels of cash (HKD $10, $20, $40), or lottery entry (HKD $1,000, $2,000, $4,000).

Main Results:

  • Incentives increased response rates compared to no incentive (19.8% vs. 16.8%, P =.012).
  • Cash incentives were more effective than lottery incentives (27.3% vs. 19.4%, P =.017).
  • The $20 cash incentive was the most cost-effective intervention per responder.

Conclusions:

  • Cash incentives, particularly at the $20 level, are effective and cost-efficient for improving mailed survey response rates.
  • Further research into incentive strategies for epidemiologic studies is recommended.

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