title: Meta-analysis of randomized controlled trials supports the use of incentives for inducing response to electronic health surveys.
abstract: OBJECTIVE
  The objective of this meta-analysis was to assess incentive effectiveness on response to electronic health surveys.
  
  
  METHODS
  A systematic literature search of PubMed, Web of Science, CINAHL, EMBASE, and the Cochrane Library was performed from 1970 to March 2013. Two authors independently selected the trials, assessed methodological quality, and extracted data. Original authors were contacted for the missing information.
  
  
  RESULTS
  The search strategy yielded nine trials (including 29,463 participants in total) that met eligibility criteria. For each of the incentive strategies examined, a random-effects model was used because of significant heterogeneity, and results were summarized as pooled odds ratios (ORs). Compared with no incentive, the offer of an incentive was seen to have a beneficial effect on response (OR, 1.48; 95% CI: 1.29, 1.71). Specifically, the odds of response were more than doubled when a monetary incentive was used (OR, 2.43; 95% CI: 1.60, 3.69) and increased when nonmonetary incentives were used (OR, 1.33; 95% CI: 1.17, 1.51).
  
  
  CONCLUSIONS
  These findings indicate that health researchers using electronic surveys can improve the quality of their research by offering incentives to potential participants.
authors.affiliation: School of Population Health, The University of Queensland, Herston Road, Herston 4006, Queensland, Australia. Electronic address: michael.david@uqconnect.edu.au.
authors.forename: Michael C
authors.initials: MC
authors.lastname: David
authors.affiliation: School of Population Health, The University of Queensland, Herston Road, Herston 4006, Queensland, Australia.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Ware
mesh_terms: D006306:Health Surveys / Q000379:methods*; D006801:Humans; D020407:Internet; D009042:Motivation; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000592:standards*
keywords: Data collection; Electronic survey; Incentives; Meta-analysis; Response; Systematic review