METHODOLOGY: Systematic reviews with NMAs within the specialty of Endodontics published in English were identified from the PubMed, EbBSCOhost and SCOPUS databases from inception to July 2021. Two reviewers were involved independently in the selection of the reviews, data extraction, methodological quality assessment and overall confidence rating. Disagreements were resolved by discussion between the reviewers to achieve consensus; if disagreements persisted, a third reviewer made the final decision. The methodological quality of the included NMAs was appraised using the AMSTAR 2 checklist, which contains 16 items. The reviewers scored each item - 'Yes' - when the item was fully addressed, 'Partial Yes' - when the item was not fully addressed, or 'No' - when the item was not addressed. The overall confidence in the results of each review was classified as 'High', 'Moderate', 'Low' or 'Critically low' based on the criteria reported by the AMSTAR 2 developers.
RESULTS: Twelve systematic reviews with NMAs were included. All the NMAs adequately reported Item 1 ("Did the research questions and inclusion criteria for the review include the components of PICO?"), Item 8 ("Did the review authors describe the included studies in adequate detail?"), Item 9 ("Did the review authors use a satisfactory technique for assessing the risk of bias (RoB) in individual studies that were included in the review?") and Item 16 ("Did the review authors report any potential sources of conflict of interest, including any funding they received for conducting the review?") , whereas only one NMA reported Item 10 adequately ("Did the review authors report on the sources of funding for the studies included in the review?"). The overall confidence in the results of eight reviews was categorised as "Critically low", one review was "Low", two reviews were "Moderate" and one review was "High".
CONCLUSION: The overall confidence in the results for the majority of systematic reviews with NMAs in Endodontics was judged to be 'Critically low' as their methodological quality was below the necessary standard. AMSTAR 2 and PRISMA for NMA guidelines are available to guide authors to produce high quality systematic reviews with NMAs and for Editors and peer-reviewers when assessing submissions to journals.
METHODS: The current investigation extends a recently published study in the International Endodontic Journal (Nagendrababu V, Faggion Jr CM, Pulikkotil SJ, Alatta A, Dummer PM Methodological assessment and overall confidence in the results of systematic reviews with network meta-analyses in Endodontics. International Endodontic Journal 2022;55:393-404) that assessed the methodological quality of systematic reviews with NMAs in Endodontics using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR 2) tool. In the present study, the PRISMA for NMA checklist with 32 items was used to assess the reporting quality of the systematic reviews with NMAs (n = 12). Two independent assessors assigned '1' when an item was completely addressed, '0.5' when it was partially addressed, and '0' when it was not addressed. Disagreements were resolved through reviewer discussion until consensus was reached. If conflicts persisted, a third reviewer made the final decision. The PRISMA for NMA scores were shared with the relevant authors of the individual reviews to reduce the likelihood of misinterpretation and verify the scores assigned. The results for each individual item of the PRISMA-NMA items were calculated by summing the individual scores awarded; the maximum score for each item was 12.
RESULTS: All the systematic reviews with NMAs adequately reported the following items: Title, Introduction section (Objectives), Methods section (Eligibility criteria and Information sources), Results section (Study selection, Study characteristics and Risk of bias within studies), and Discussion section (Summary of evidence). The items that were reported least often were the "geometry of the network" and "the summary of network geometry" with only 2 manuscripts (17%) including these items.
CONCLUSION: A number of the items in the PRISMA-NMA checklist were adequately addressed in the NMAs; however, none adequately reported all the PRISMA-NMA items. The inadequacies of published NMAs that have been identified should be taken into consideration by authors of NMAs in Endodontics and by editors when managing the peer review process. In future, researchers who are writing systematic reviews with NMAs should comply with the PRISMA-NMA checklist.
CLINICAL RELEVANCE: None of the included systematic reviews with NMA adequately reported all the PRISMA-NMA items. Inadequate reporting of a systematic review with NMA increases the possibility that it will provide invalid results. Therefore, authors should follow the PRISMA-NMA guidelines when reporting systematic reviews with NMA in Endodontics.