Meta-analysis is a powerful tool to synthesize findings from multiple studies. The normal-normal random-effects model is widely used to account for between-study heterogeneity. However, meta-analyses of sparse data, which may arise when the event rate is low for binary or count outcomes, pose a challenge to the normal-normal random-effects model in the accuracy and stability in inference since the normal approximation in the within-study model may not be good. To reduce bias arising from data sparsity, the generalized linear mixed model can be used by replacing the approximate normal within-study model with an exact model. Publication bias is one of the most serious threats in meta-analysis. Several quantitative sensitivity analysis methods for evaluating the potential impacts of selective publication are available for the normal-normal random-effects model. We propose a sensitivity analysis method by extending the likelihood-based sensitivity analysis with the $t$-statistic selection function of Copas to several generalized linear mixed-effects models. Through applications of our proposed method to several real-world meta-analyses and simulation studies, the proposed method was proven to outperform the likelihood-based sensitivity analysis based on the normal-normal model. The proposed method would give useful guidance to address publication bias in the meta-analysis of sparse data.

The summary receiver operating characteristic (SROC) curve has been recommended as one important meta-analytical summary to represent the accuracy of a diagnostic test in the presence of heterogeneous cutoff values. However, selective publication of diagnostic studies for meta-analysis can induce publication bias (PB) on the estimate of the SROC curve. Several sensitivity analysis methods have been developed to quantify PB on the SROC curve, and all these methods utilize parametric selection functions to model the selective publication mechanism. The main contribution of this article is to propose a new sensitivity analysis approach that derives the worst-case bounds for the SROC curve by adopting nonparametric selection functions under minimal assumptions. The estimation procedures of the worst-case bounds use the Monte Carlo method to approximate the bias on the SROC curves along with the corresponding area under the curves, and then the maximum and minimum values of PB under a range of marginal selection probabilities are optimized by nonlinear programming. We apply the proposed method to real-world meta-analyses to show that the worst-case bounds of the SROC curves can provide useful insights for discussing the robustness of meta-analytical findings on diagnostic test accuracy.

In medical research, publication bias (PB) poses great challenges to the conclusions from systematic reviews and meta-analyses. The majority of efforts in methodological research related to classic PB have focused on examining the potential suppression of studies reporting effects close to the null or statistically non-significant results. Such suppression is common, particularly when the study outcome concerns the effectiveness of a new intervention. On the other hand, attention has recently been drawn to the so-called inverse publication bias (IPB) within the evidence synthesis community. It can occur when assessing adverse events because researchers may favor evidence showing a similar safety profile regarding an adverse event between a new intervention and a control group. In comparison to the classic PB, IPB is much less recognized in the current literature; methods designed for classic PB may be inaccurately applied to address IPB, potentially leading to entirely incorrect conclusions. This article aims to provide a collection of accessible methods to assess IPB for adverse events. Specifically, we discuss the relevance and differences between classic PB and IPB. We also demonstrate visual assessment through contour-enhanced funnel plots tailored to adverse events and popular quantitative methods, including Egger\'s regression test, Peters\' regression test, and the trim-and-fill method for such cases. Three real-world examples are presented to illustrate the bias in various scenarios, and the implementations are illustrated with statistical code. We hope this article offers valuable insights for evaluating IPB in future systematic reviews of adverse events.

Objectives: Exploring the relationship between the hOGG1 rs1052133 polymorphism and the occurrence of nasopharyngeal carcinoma (NPC). Methods: PubMed, Web of Science, Scopus, CNKI, Wanfangdata, and VIP were used to search for studies and the NOS evaluation scale was used to evaluate the quality. All studies were grouped according to different genotypes. The Cochrane\'s Q test and I2 test were used for heterogeneity evaluations. If heterogeneity was small, the fixed effects model was used, and conversely, the random effects model was used. Publication bias was also detected. P < .05 in all results indicated statistically significant. Results: We ultimately included 6 studies with 2021 NPC patients in the study group and 2375 healthy populations in the control group. After meta-analysis, it was found that the total OR value of the \"Ser/Cys (CG) vs Ser/Ser (CC)\" group was 1.00 (95% CI: 0.85-1.18) and the \"Cys/Cys (GG) vs Ser/Ser (CC)\" group was 1.06 (95% CI: 0.87-1.28). These results were not statistically significant (P > .05). Furthermore, the integrated total OR values of each group were not statistically significant with or without the smoking history, even in other genotype models (Allele, Dominant, Recessive, and Additive) (P > .05). Conclusion: There is no clear correlation between the hOGG1 rs1052133 polymorphism and the occurrence of NPC, even with or without the smoking history.

BACKGROUND: Previous literature has explored the relationship between chronic atrophic gastritis (CAG) and isolated cancers within the upper gastrointestinal cancers; However, an integrative synthesis across the totality of upper gastrointestinal cancers was conspicuously absent. The research objective was to assess the relationship between CAG and the risk of incident upper gastrointestinal cancers, specifically including gastric cancer, oesophageal cancer, and oesophagogastric junction cancer.
METHODS: Rigorous systematic searches were conducted across three major databases, namely PubMed, Embase and Web of Science, encompassing the timeline from database inception until August 10, 2023. We extracted the necessary odds ratio (OR) and their corresponding 95% confidence interval (CI) for subsequent meta-analysis. Statistical analyses were conducted using Stata 17.0 software.
RESULTS: This meta-analysis included a total of 23 articles encompassing 5858 patients diagnosed with upper gastrointestinal cancers. CAG resulted in a statistically significant 4.12-fold elevated risk of incident gastric cancer (OR = 4.12, 95% CI 3.20-5.30). Likewise, CAG was linked to a 2.08-fold increased risk of incident oesophageal cancer (OR = 2.08, 95%CI 1.60-2.72). Intriguingly, a specific correlation was found between CAG and the risk of incident oesophageal squamous cell carcinoma (OR = 2.29, 95%CI 1.77-2.95), while no significant association was detected for oesophageal adenocarcinoma (OR = 0.62, 95%CI 0.17-2.26). Moreover, CAG was correlated with a 2.77-fold heightened risk of oesophagogastric junction cancer (OR = 2.77, 95%CI 2.21-3.46). Notably, for the same type of upper gastrointestinal cancer, it was observed that diagnosing CAG through histological methods was linked to a 33-77% higher risk of developing cancer compared to diagnosing CAG through serological methods.
CONCLUSIONS: This meta-analysis indicated a two- to fourfold increased risk of gastric cancer, oesophageal cancer, and oesophagogastric junction cancer in patients with CAG. Importantly, for the same upper gastrointestinal cancer, the risk of incident cancer was higher when CAG was diagnosed histologically compared to serological diagnosis. Further rigorous study designs are required to explore the impact of CAG diagnosed through both diagnostic methods on the risk of upper gastrointestinal cancers.

OBJECTIVE: This meta-analysis of observational studies aimed to derive a more precise estimation of the relationship between postpartum pain and postpartum depression (PPD).
METHODS: A systematic literature search was completed in the following databases from inception to September 26, 2022: PubMed, Embase, and Web of Science. Quality evaluation of each study was achieved through Newcastle-Ottawa scale (NOS) assessment. Heterogeneity across studies was evaluated by Cochran\'s Q test and I2 test. Pooled estimates of odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were analyzed using fixed-effects model or random-effects model, according to heterogeneity. Subgroup analysis, sensitivity analysis, and Egger\'s test were also performed.
RESULTS: From the identified 1884 articles, a total of 8 studies involving 3973 participants were included in the final meta-analysis. Seven of the 8 studies were evaluated as high-quality, with NOS scores ≥7. A significant heterogeneity was observed (I2  = 66.5%, p = 0.004) among eight studies. Therefore, the performed random-effect model suggested a significant association between postpartum pain and PPD risk (OR 1.29, 95% CI 1.10-1.52, p = 0.002). However, the subgroup analyses did not define the source of heterogeneity. Moreover, the sensitivity analysis showed the stability of the pooled results, but the significant publication bias was identified (p = 0.009). The trim and fill method was performed and resulted in an OR of 1.14 (95% CI 0.95-1.37, p = 0.162).
CONCLUSIONS: This meta-analysis found a potential association between postpartum pain and PPD. Further researches are needed to provide more robust evidences.

OBJECTIVE: To evaluate the report quality, methodological quality and evidence quality of the systematic reviews and meta-analyses (SRs/MAs) of acupuncture for in vitro fertilization-embryo transfer (IVF-ET).
METHODS: The SRs/MAs of acupuncture for IVF-ET were searched electronically from databases of CNKI, Wanfang, VIP, SinoMed, PubMed, Embase, Cochrane Library, from inception of each database to September 27th, 2022. Two reviewers independently screened the literature and extracted the data. Using PRISMA statement, the AMSTAR 2 scale and the GRADE system, the report quality, methodological quality and evidence quality of the included SRs/MAs were assessed.
RESULTS: A total of 28 SRs/MAs were included, with PRISMA scores ranging from 8.5 points to 27 points. The problems of report quality focused on protocol and registration, retrieval, risk of bias in studies, additional analysis, limitations and funding. The methodological quality of included studies was generally low, reflecting on items 2, 3, 7, 10, 12 and 16. A total of 85 outcome indexes were included in the GRADE system for evidence grade evaluation. Most of the evidences were low or very low in quality. The reasons for the downgrade were related to study limitations, inconsistency, imprecision and publication bias.
CONCLUSIONS: Acupuncture therapy improves the outcomes of IVF-ET, but the methodological quality and evidence quality of related SRs/MAs are low. It is recommended to conduct more high-quality studies in the future to provide more reliable evidences.
目的: 对针灸辅助体外受精胚胎移植（IVF-ET）的系统评价（SR）/Meta分析（MA）进行报告质量、方法学质量和证据质量的再评价。方法: 计算机检索中国期刊全文数据库（CNKI）、万方数据知识服务平台（Wanfang）、维普中文期刊服务平台（VIP）、中国生物医学文献数据库（SinoMed）、PubMed、EMbase、Cochrane Library中针灸辅助IVF-ET的SR/MA。检索时限均为建库至2022年9月27日。由2名研究员独立筛选文献、提取资料后，采用PRISMA声明、AMSTAR 2量表和GRADE系统分别评价纳入SR/MA的报告质量、方法学质量和证据质量。结果: 共纳入28篇SR/MA，PRISMA评分在8.5～27分。报告质量问题主要表现在方案和注册、检索、研究偏倚、其他分析、局限性、资金支持等方面。纳入研究的方法学质量整体偏低，问题主要集中在条目2、3、7、10、12、16。共85个结局指标纳入GRADE系统进行证据等级评价，大部分证据质量为低或极低，降级的原因主要与研究的局限性、不一致性、不精确性和发表偏倚有关。结论: 针灸辅助IVF-ET治疗可以改善不孕患者的妊娠结局，但相关SR/MA的方法学质量和证据质量均较低，建议今后开展更多高质量的研究以提供更可靠的循证依据。.

Objective: The pathogenesis of leukemia is complex and there are no effective diagnostic and prognostic indicators. Previous studies showed that microRNA-22 (miR-22) has altered expression level in multiple leukemia subtypes, which is associated with the survival outcomes of leukemia. Methods: According to the constituted retrieval strategy, eligible studies were included from January 2010 to November 2022 by searching database. The pooled Risk Ratio (RR) and 95% confidence intervals (CI) were used to study the relationship between miR-22 and survival. Stata12.0 was used for meta-analysis. Differential expression analysis was conducted based on expression profile of miRNA. Results: Four English articles were included containing a total of 215 leukemia patients. Data showed that the pooled RR for overall survival (OS) was 1.558 (95% CI: 1.197-2.028, P < .01). Subgroup analysis for OS of acute myeloid leukemia patients and the RFS of plasma cell leukemia patients were statistically significant with different expression levels of miR-22 (RR:1.495, 95%CI:1.141-1.958, P < .01 and RR:1.517, 95%CI:1.114-2.065, P < .01, respectively). Moreover, all data included had no significant heterogeneity and publication bias. Conclusions: miR-22 is associated with the survival outcome of leukemia patients suggesting that miR-22 may be a promising prognostic biomarker for this patient population, and the expression level of miR-22 in ALL patients down-regulated.

In this study, we aim to evaluate the efficacy and safety of acupuncture for vocal nodules, concerning qualitive overall efficacy and quantitative improvement on quality of voice. Four English and four Chinese databases were searched up to December 10th, 2022. Risk of bias among the included trials were evaluated by the Cochrane ROB tool. Systematic reviews and meta-analyses were conducted based on the Cochrane systematic review method by using RevMan 5.4 Software, and trial sequential analyses were performed by TSA 0.9. Meta-influence analyses, subgroup-analyses, meta-regression, and evaluation of publication bias were performed for exploration of heterogeneity by Stata V.14. Quality of the results was accessed through the GRADE-pro GDT. Cluster analyses and correlation coefficient were performed by R 4.1.3. Finally, 15 trials involving 1,888 participants were included. Results showed that compared with western medicine alone or Chinese herbal medicine alone, acupuncture alone yielded significantly (p<0.05) higher clinical effective rate and more improvement on scores of voice analyses. However, reduction on scores of grade, roughness, and breathiness and voice handicap index during follow-ups, and results of clinical effective rate suggested that acupuncture was inferior to voice training. In addition, meta-regression and sub-group analyses firstly revealed advanced efficacies of acupuncture when performed with local and remote acupoints, compared with local acupoints only. Acupuncture specified adverse event was denied in six trials while it was not mentioned in other nine trials. Results of cluster analyses and correlation coefficient showed that Kai yin yi hao and He gu (LI-4) were the most frequently applied matching-acupoints in trials. In conclusion, compared with western medicine (level of evidence: low ⨁⨁◯◯, GRADE C) and Chinese herbal medicine (level of evidence: moderate ⨁⨁⨁◯, GRADE B), acupuncture is safe and of better efficacy for patients with vocal nodules, while there is also need for RCTs with improvements on designing and interventions in experimental and controls.

OBJECTIVE: To assess the methodological quality, report quality and evidence quality of the Meta-analysis and systematic reviews of acupuncture and moxibustion for children with cerebral palsy, aiming to provide decision-making basis for clinical treatment.
METHODS: The systematic reviews and Meta-analysis of acupuncture and moxibustion for children with cerebral palsy were searched in CNKI, Wanfang, VIP, SinoMed, Cochrane Library, PubMed and EMbase. The retrieval time was from the database establishment to June 30th, 2022. AMSTAR 2 (a measurement tool to assess systematic reviews) was used to evaluate the methodological quality， and PRISMA (preferred reporting items for systematic reviews and Meta-analyses) was used to evaluate the report quality, and GRADE was used to evaluate the quality of evidence.
RESULTS: A total of 14 systematic reviews were included, including 37 primary outcome indexes. According to AMSTAR 2 evaluation results, there were 4 low quality studies, 10 very low quality studies, and low scores on items 2, 4, 7, 10 and 16. PRISMA scores ranged from 15 to 25, and the main reporting problems reflected in structured abstracts, program and registration, retrieval, and funding sources, etc. According to the GRADE classification results, there were 3 high quality evidences, 7 medium quality evidences, 10 low quality evidences and 17 very low quality evidences. The main downgrading factors were limitations, imprecision and publication bias.
CONCLUSIONS: Acupuncture and moxibustion has a certain effect for cerebral palsy in children, but the quality of methodology, reporting and evidence in the included literature is poor, and the comparison of curative effect between different acupuncture and moxibustion methods is unclear.
目的：对针灸治疗小儿脑瘫疗效的Meta分析和系统评价进行方法学质量、报告质量和证据质量评价，为临床决策提供参考。方法：计算机检索中国期刊全文数据库（CNKI）、万方数据知识服务平台（Wanfang）、维普资讯中文期刊服务平台（VIP）、中国生物医学文献服务系统（SinoMed）、Cochrane Library、PubMed 和EMbase数据库，收集针灸治疗小儿脑瘫疗效的系统评价/Meta分析，检索时间为建库至2022年6月30日。使用AMSTAR 2量表评估文献的方法学质量，使用PRISMA量表对文献报告质量进行评分，使用GRADE量表对证据质量进行分级。结果：最终纳入14篇系统评价，共37个结局指标，通过AMSTAR 2评价纳入文献的方法学质量，4篇为低质量，10篇为极低质量文献，得分较差的条目为2、4、7、10、16。PRISMA评分为15~25分，报告质量问题主要体现为结构式摘要、方案和注册、检索、资金等方面。GRADE分级结果显示，高质量证据3个，中等质量证据7个，低质量证据10个，极低质量证据17个，降级因素主要为局限性、不精确性及发表偏倚。结论：针灸治疗小儿脑瘫有一定疗效，但纳入文献的方法学质量、报告质量、证据质量均较差，且不同针灸方法之间的疗效比较尚不明确。.