Action taken
RECRUITMENT
Upon discovery of the suspicious activity, we promptly reported the incident to our independent study steering Committee, the research funder (National Institute for Health and Care Research), the University of Leeds School of Medicine Research Ethics Committee that had approved the study, and the study sponsor. We submitted a report to NHS Counter Fraud and then to the Department of Health and Social Care as the ultimate study funder. We informed our Patient and Public Involvement panel, which expressed concern about the misuse of public funding.We revised the study recruitment materials (email invitation and study landing page) to emphasise that participants should complete the study once only. We enhanced study security by adding a screening page prior to study entry. This required participants to submit an NHS or Health and Social Care (Northern Ireland; HSCNI) email address before proceeding. The submitted email address was then subjected to two automated checks: first, whether it had been submitted previously, and second, whether it was a plausible NHS or HSCNI email address. Anyone attempting to use an address rejected by either check was unable to proceed.We subsequently relaunched the online trial for a pre-specified period (5 September 2019 to 18 October 2019). By the end of the second recruitment period, there were a total 1241 randomisations and 1113 experiment completions, including a total 1080 voucher requests. During the second recruitment period, we identified two experiment completions associated with two similar NHS email addresses (Table We shared a written summary of our evidence with the general practice that we had linked to the unusual trial activity. We received a response from the senior partner expressing concern that they had been affected by ‘cybercrime’. We did not send any vouchers to the duplicated email addresses.