A Cross-Sectional Study Based on Forty Systematic Reviews of Foods with Function Claims (FFC) in Japan: Quality Assessment Using AMSTAR 2

Investigate the relationship between the retraction reasons and the quality of methodology in non-Cochrane retracted systematic reviews: a systematic review

BACKGROUND

This systematic review aimed to investigate the relationship between retraction status and the methodology quality in the retracted non-Cochrane systematic review.

METHOD

PubMed, Web of Science, and Scopus databases were searched with keywords including systematic review, meta-analysis, and retraction or retracted as a type of publication until September 2023. There were no time or language restrictions. Non-Cochrane medical systematic review studies that were retracted were included in the present study. The data related to the retraction status of the articles were extracted from the retraction notice and Retraction Watch, and the quality of the methodology was evaluated with the AMSTAR-2 checklist by two independent researchers. Data were analyzed in the Excel 2019 and SPSS 21 software.

RESULT

Of the 282 systematic reviews, the corresponding authors of 208 (73.75%) articles were from China. The average interval between publish and retraction of the article was about 23 months and about half of the non-Cochrane systematic reviews were retracted in the last 4 years. The most common reasons for retractions were fake peer reviews and unreliable data, respectively. Editors and publishers were the most retractors or requestors for retractions. More than 86% of the retracted non-Cochrane SRs were published in journals with an impact factor above two and had a critically low quality. Items 7, 9, and 13 among the critical items of the AMSTAR-2 checklist received the lowest scores.

DISCUSSION AND CONCLUSION

There was a significant relationship between the reasons of retraction and the quality of the methodology (P-value < 0.05). Plagiarism software and using the Cope guidelines may decrease the time of retraction. In some countries, strict rules for promoting researchers increase the risk of misconduct. To avoid scientific errors and improve the quality of systematic reviews/meta-analyses (SRs/MAs), it is better to create protocol registration and retraction guidelines in each journal for SRs/MAs.

[A Study on the Scientific Reliability of Notification Data in the Foods with Function Claims]

We conducted a comprehensive survey of Foods with Function Claims (FFC) submitted from April to August 2022 to examine the scientific reliability of the systematic review (SR), which is the basis for functional claims. The results of the review of 611 functional claims for 398 products showed that there were 121 functionally active substances and 87 health claims (Hc) that were labeled, with some functionally active substances having multiple functions. SRs, meta-analyses, and clinical studies were submitted as the basis of functionality for 87%, 10%, and 3% of the reports, respectively. Of these SRs, 39% of the SRs included a single paper. In 67% of the SRs with a single paper included, some of the authors of the included paper and the person who conducted the SR had the same affiliation, which raises concerns about conflicts of interest. The median of clinical trial participants in papers included for SR was relatively small, 38, and the smallest total number of SRs was 6. Thus, it was shown that there are many SRs for FFC that are based on only a single paper or a small-scale clinical trial and that lack reliability as scientific evidence.

[Current Status and Issues on the Foods with Function Claims System in Japan: Evidence of Functionality of the Foods]

The purpose of this narrative review was to clarify the current status and issues of scientific evidence for functionality in the Foods with Function Claims system based on previous research. From the introduction of the system in April 2015 to January 1, 2023, there were 6606 notifications, of which 6297 (95.3) were systematic reviews (SRs) and 309 (4.7%) were clinical trials (CTs). SRs were identified the following problems: i) inadequate description based on the first version of PRISMA checklist, and ii) very low levels of quality assessment in the first version of AMSTAR checklist and AMSTAR 2. CT was reported to have the following problems: i) inconsistencies between the protocol and the content in the paper (non-compliance), ii) high risk of bias, and iii) not described based on the CONSORT 2010 checklist. Since SRs and randomized controlled trials (RCTs) often have low-quality notifications, it is necessary to correctly communicate this information to consumers in order to make appropriate purchasing decisions.