A randomised controlled trial of the 5:2 diet
Assessed by RV014 · Research Fellow
Assessed on 5 Nov 2025
OverallReviewer's overall integrity assessment, derived from all research questions No concerns
DOI 10.1371/journal.pone.0258853 (opens in new tab)
Resource ripekg:research-integrity-assessment/RIPEA77B6E86E8A5311B0
5 Research Questions · 3 Evidence Items
Q1.1 — Does the study have an associated retraction?
Rationale: I agree with INSPECT-AI
Q1.2 — Does the study have an associated expression of concern or other relevant post-publication notice?
Rationale: I agree with INSPECT-AI
Q1.3 — Do other studies by the research team highlight causes for concern?
Rationale: I agree with INSPECT-AI that the authors are associated with retractions. The two authors are associated with the same retracted paper. This appears to have been retracted by the author group due to coding errors in the analysis. This suggests the author group have integrity and I think it's unclear whether this causes integrity concerns for the main article.
Supporting Evidence (1)
Retraction NoticeSource: Retraction Watch database
Efficacy of Electronic Cigarettes vs Varenicline and Nicotine Chewing Gum as an Aid to Stop Smoking: A Randomized Clinical Trial
10.1001/jamainternmed.2024.1125 (opens in new tab)RetractionWatch ID:Record identifier in the Retraction Watch database 52992
Rationale: Error in Analyses;Error in Methods;Error in Results and/or Conclusions
About Authors: Peter Hajek, Francesca Pesola
Q2.2 — Are there concerns relating to the timing or absence of study registration?
Rationale: I agree with INSPECT-AI that the registration date is retrospective; however, the entry in ISRCTN shows the submission date is 19th July 2016 (so only three weeks after recruitment start date of 27th June 2016). The registration date is 21st July 2016 but the overall study start date given in ISRCTN is 1st November 2015 and the first enrolment date is document in ISRTCN (so it appears the authors are transparent about the retrospective registration date). Ethics approval was granted on 29/02/2016, ref: 16/LO/0073
Supporting Evidence (2)
Clinical Trial RegistrationSource: Clinical trial registry (e.g. ClinicalTrials.gov, ISRCTN)
Registration ID: ISRCTN79408248
Registry: ISRCTN
Registry Link: https://trialsearch.who.int/Trial2.aspx?TrialID=ISRCTN79408248 (opens in new tab)
Registration Date: 21/07/2016
Prospective:Whether the trial was registered before participant recruitment began No
Assessment Rationale:How INSPECT-AI determined the prospective registration status by comparing dates Registration date is after LLM recruitment start date.
Study Design EvidenceDates and timelines extracted by INSPECT-AI from the publication text
Recruitment Start: 27-06-2016
Recruitment Start Rationale:INSPECT-AI's reasoning for how it identified the recruitment start date Results section: 'A total of 300 participants were recruited between 27 June 2016 and 15 June 2018, and followed up for one year.'
Recruitment End: 15-06-2018
Recruitment End Rationale:INSPECT-AI's reasoning for how it identified the recruitment end date Results section: 'A total of 300 participants were recruited between 27 June 2016 and 15 June 2018, and followed up for one year.'
Study End: N/A
Study End Rationale:INSPECT-AI's reasoning for how it identified the study end date No explicit study end date found. The follow-up period was one year, but the specific end date is not mentioned.
Overall — What is the overall integrity assessment of the study?
Rationale: I agree that the checks performed by INSPECT-AI are correct but I do not have integrity concerns after checking the reasons for the retraction associated with the two co-authors and the dates listed in ISRCTN.