Introduction: While online recruitment offers many advantages for health research, fraudulent responses can be a challenge.
Objectives: This study aimed to describe the methods used by health researchers to identify and counteract fraudulent responses during online survey recruitment.
Methods: Nine databases (Medline, Informit, AMED, CINAHL, Embase, Cochrane CENTRAL, IEEE Xplore, Scopus, and Web of Science) were searched from their inception to April 2024. Two authors independently screened, selected, and extracted data from studies, following the Joanna Briggs Institute’s scoping review methodology and PRISMA-Scoping Review guidelines. Fraud detection and mitigation strategies were evaluated using a pre-established framework.
Results: The review included 23 studies, which were categorised into methods for detecting and addressing fraudulent responses. Six studies (26%) flagged surveys completed in under five minutes as suspicious, and 12 studies (52%) identified non-conforming responses through text patterns and consistency checks. Four studies investigated abnormal completion times, and seven studies (30%) used Internet Protocol verification to address geographical discrepancies. Seventeen studies (73%) found that higher incentives increased fraudulent responses. Mitigation strategies included CAPTCHA (34%), manual checks (21%), and video verification (8%). Most studies recommended using multiple detection methods, though few rigorously evaluated their effectiveness.
Conclusion: There is limited evidence on the evaluation of fraud mitigation strategies in online health research. Researchers should adopt a combination of strategies to ensure data integrity when recruiting participants online.