Quantifying the association of sperm DNA fragmentation with assisted reproductive technology outcomes: An umbrella review.

BACKGROUND: Systematic reviews and meta-analyses are instrumental in shaping clinical practice. However, their findings can sometimes be marred by discrepancies and potential biases, thereby diluting the strength of the evidence presented. Umbrella reviews serve to comprehensively assess and synthesise these reviews, offering a clearer insight into the quality of the evidence presented. In the context of the relationship between sperm DNA fragmentation (SDF) and assisted conception outcomes, there is a divergence in the literature. Some reviews suggest a clear cause-and-effect linkage, whereas others present conflicting or inconclusive results. OBJECTIVES: In this umbrella review we aimed to synthesise the evidence collated in systematic reviews and meta-analyses summarising the association of SDF with assisted reproductive technology (ART) outcomes. SEARCH STRATEGY: After preregistration (https://doi.org/10.17605/OSF.IO/6JHDP), we performed a comprehensive search of the PubMed, Scopus, Cochrane Library, Web of Science and Embase databases. We conducted a search for systematic reviews on the association between SDF and ART without any restrictions on language or publication date. SELECTION CRITERIA: Systematic reviews and meta-analyses assessing the association between SDF and ART outcomes were eligible. DATA COLLECTION AND ANALYSIS: We assessed the quality of the included reviews using AMSTAR 2 and ROBIS, and determined the degree of overlap of primary studies between reviews estimating the corrected covered area (CCA), adjusted for structural missingness. We evaluated the most recent reviews assessing the association of SDF with live birth, pregnancy, miscarriage, implantation, blastulation and fertilisation. The synthesis of evidence was harmonised across all included quantitative syntheses, re-estimating the odds ratio (eOR) in random-effects meta-analyses with 95% confidence intervals (95% CIs) and 95% prediction intervals (95% PIs). We categorised the evidence strength into convincing, highly suggestive, suggestive, weak or nonsignificant, according to the meta-analysis re-estimated P-value, total sample size, I2 statistic for heterogeneity, small study effect, excess significance bias and the largest study significance. MAIN RESULTS: We initially captured and screened 49 332 records. After excluding duplicate and ineligible articles, 22 systematic reviews, 15 of which were meta-analyses, were selected. The 22 reviews showed a moderate degree of overlap (adjusted CCA 9.2%) in their included studies (overall n = 428, with 180 unique studies). The 15 meta-analyses exhibited a high degree of overlap (adjusted CCA = 13.6%) in their included studies (overall n = 274, with 118 unique studies). AMSTAR 2 categorised the quality of evidence in 18 reviews as critically low and the quality of evidence in four reviews as low. ROBIS categorised all the reviews as having a high risk of bias. The re-estimated results showed that the association of SDF with live birth was weak in one and nonsignificant in four meta-analyses. Similarly, the association of SDF with pregnancy, miscarriage, implantation, blastulation and fertilisation was also weak or nonsignificant. The association of high SDF with different ART outcomes was also weak or nonsignificant for different interventions (IVF, ICSI and IUI) and tests. CONCLUSIONS: This umbrella review did not find convincing or suggestive evidence linking SDF with ART outcomes. Caution should be exercised in making any claims, policies or recommendations concerning SDF.

Post-publication research integrity concerns in randomized clinical trials: A scoping review of the literature.

BACKGROUND: Post-publication handling of integrity concerns in randomized clinical trials (RCTs) is a contentious matter. OBJECTIVES: We undertook a scoping systematic review to map the literature regarding post-publication integrity issues in RCTs. SEARCH STRATEGY AND SELECTION CRITERIA: Following prospective registration (https://osf.io/pgxd8) we initially searched PubMed and Scopus but subsequently extended it to include the Cochrane Library, and Google Scholar databases without language, article type or publication time restriction until November 2022. Reviewers independently selected published articles covering any aspect of post-publication research integrity concerns in RCTs. DATA COLLECTION AND ANALYSIS: The study findings grouped within domains relating to issues concerning post-publication integrity were extracted in duplicate, verified by a third reviewer, and then tabulated. MAIN RESULTS: The initial search captured 3159 citations, of which 89 studies were included in the review. Cross-sectional studies constituted the majority of included studies (n = 34, 38.2%), followed by systematic reviews (n = 10, 11.2%), methodology reviews/studies (n = 9, 10.1%) and other types of descriptive studies (n = 8, 9.0%). A total of 21 articles (23.6%) covered the domain on general issues, 25 (28.1%) in the journal's instructions and policies domain, eight (9.0%) in the editorial and peer review domain, one (1.1%) in the correspondence and complaints (post-publication peer review) domain, 12 (13.5%) in the investigation for concerns domain, six (6.7%) in the post-investigation decisions and sanctions domain, none in the critical appraisal guidance domain, five (5.6%) in the integrity assessment in systematic reviews domain, and 26 (29.2%) in the recommendations for future research domain. A total of 12 of the selected articles (13.5%) covered two (n = 9) or three (n = 3) different domains. CONCLUSIONS: Various research integrity domains and issues covering post-publication aspects of RCT integrity were captured and gaps were identified, mostly related with the necessary implications for all stakeholders to improve research transparency. There is an urgent need for a multistakeholder consensus towards creating specific statements for addressing post-publication integrity concerns in RCTs.