Meta-analysis with zero-event studies: a comparative study with application to COVID-19 data

Predictors for Long-Term Survival After Resection of Pancreatic Ductal Adenocarcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Improved systemic therapy has made long term (≥ 5 years) overall survival (LTS) after resection of pancreatic ductal adenocarcinoma (PDAC) increasingly common. However, a systematic review on predictors of LTS following resection of PDAC is lacking.

METHODS

The PubMed, Embase, Scopus, and Cochrane CENTRAL databases were systematically searched from inception until March 2023. Studies reporting actual survival data (based on follow-up and not survival analysis estimates) on factors associated with LTS were included. Meta-analyses were conducted by using a random effects model, and study quality was gauged by using the Newcastle-Ottawa Scale (NOS).

RESULTS

Twenty-five studies with 27,091 patients (LTS: 2,132, non-LTS: 24,959) who underwent surgical resection for PDAC were meta-analyzed. The median proportion of LTS patients was 18.32% (IQR 12.97-21.18%) based on 20 studies. Predictors for LTS included sex, body mass index (BMI), preoperative levels of CA19-9, CEA, and albumin, neutrophil-lymphocyte ratio, tumor grade, AJCC stage, lymphovascular and perineural invasion, pathologic T-stage, nodal disease, metastatic disease, margin status, adjuvant therapy, vascular resection, operative time, operative blood loss, and perioperative blood transfusion. Most articles received a "good" NOS assessment, indicating an acceptable risk of bias.

CONCLUSIONS

Our meta-analysis pools all true follow up data in the literature to quantify associations between prognostic factors and LTS after resection of PDAC. While there appears to be evidence of a complex interplay between risk, tumor biology, patient characteristics, and management related factors, no single parameter can predict LTS after the resection of PDAC.

The prevalence of antimicrobial drug resistance of non-typhoidal Salmonella in human infections in sub-Saharan Africa: a systematic review and meta-analysis

INTRODUCTION

Non-typhoidal Salmonella (NTS) bacteremia is common in sub-Saharan Africa. We examined the prevalence of antibiotic resistance to fluoroquinolones, third-generation cephalosporins, and multi-drug resistance (MDR) in NTS human isolates from sub-Saharan Africa.

METHODS

A systematic review was conducted using a search in Ovid Medline, Embase, and African Index Medicus of publications between 2000 and 2021. A random-effects model meta-analysis was performed using data from 66 studies that included 29,039 NTS blood and 1,065 stool isolates.

RESULTS

The pooled prevalence proportions of MDR were 0.685 (95% CI 0.574-0.778) and 0.214 (0.020-0.785) in blood vs. stool isolates. The corresponding estimates of fluoroquinolones resistance were 0.014 (0.008-0.025) vs. 0.021 (0.012-0.036) and third-generation cephalosporins resistance 0.019 (0.012-0.031) vs. 0.035 (0.006-0.185). Similar results were found for children and adults. Resistance prevalence to these antibiotics in blood isolates increased between 2000-2010 and 2011-2021. The guidelines employed to determine antimicrobial resistance and epidemiological characteristics (e.g. sample size, study duration) correlated with the resistance prevalence.

CONCLUSIONS

The prevalence of MDR and resistance to fluoroquinolones and third-generation cephalosporins in NTS in sub-Saharan Africa is alarming.

EXPERT OPINION

Standardized surveillance of antimicrobial drug resistance in NTS in sub-Saharan Africa is warranted to guide healthcare policymaking and antibiotic stewardship programs.

Enhanced Recovery After Surgery Guidelines and Hospital Length of Stay, Readmission, Complications, and Mortality: A Meta-Analysis of Randomized Clinical Trials

Importance

A comprehensive review of the evidence exploring the outcomes of enhanced recovery after surgery (ERAS) guidelines has not been completed.

Objective

To evaluate if ERAS guidelines are associated with improved hospital length of stay, hospital readmission, complications, and mortality compared with usual surgical care, and to understand differences in estimates based on study and patient factors.

Data Sources

MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central were searched from inception until June 2021.

Study Selection

Titles, abstracts, and full-text articles were screened by 2 independent reviewers. Eligible studies were randomized clinical trials that examined ERAS-guided surgery compared with a control group and reported on at least 1 of the outcomes.

Data Extraction and Synthesis

Data were abstracted in duplicate using a standardized data abstraction form. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Risk of bias was assessed in duplicate using the Cochrane Risk of Bias tool. Random-effects meta-analysis was used to pool estimates for each outcome, and meta-regression identified sources of heterogeneity within each outcome.

Main Outcome and Measures

The primary outcomes were hospital length of stay, hospital readmission within 30 days of index discharge, 30-day postoperative complications, and 30-day postoperative mortality.

Results

Of the 12 047 references identified, 1493 full texts were screened for eligibility, 495 were included in the systematic review, and 74 RCTs with 9076 participants were included in the meta-analysis. Included studies presented data from 21 countries and 9 ERAS-guided surgical procedures with 15 (20.3%) having a low risk of bias. The mean (SD) Reporting on ERAS Compliance, Outcomes, and Elements Research checklist score was 13.5 (2.3). Hospital length of stay decreased by 1.88 days (95% CI, 0.95-2.81 days; I2 = 86.5%; P < .001) and the risk of complications decreased (risk ratio, 0.71; 95% CI, 0.59-0.87; I2 = 78.6%; P < .001) in the ERAS group. Risk of readmission and mortality were not significant.

Conclusions and Relevance

In this meta-analysis, ERAS guidelines were associated with decreased hospital length of stay and complications. Future studies should aim to improve implementation of ERAS and increase the reach of the guidelines.

Do blood concentrates influence inflammatory signs and symptoms after mandibular third molar surgery? A systematic review and network meta-analysis of randomized clinical trials

OBJECTIVES

To investigate, through a network meta-analysis, the effectiveness of blood concentrates in reducing pain perception, trismus, and edema after mandibular third molar extraction.

MATERIALS AND METHODS

An electronic search was performed in nine databases to locate randomized clinical trials comparing blood concentrate use after mandibular third molar extraction. Two authors selected and extracted the data independently. The individual risk of bias in the studies was assessed with the RoB v2.0 tool. A network meta-analysis compared postoperative pain and trismus scores after applying different blood concentrates, using the mean difference (MD) as an effect estimate. The GRADE approach assessed the certainty of evidence.

RESULTS

Thirty-one randomized clinical trials were included in the review and 18 in the meta-analysis. Leukocyte- and platelet-rich fibrin (L-PRF) was the most used blood concentrate, followed by platelet-rich plasma (PRP). The network meta-analysis, depending on the analyzed period, evaluated up to 1240 surgeries. Among the analyzed blood concentrates, advanced platelet-rich fibrin (A-PRF) performed better among the analyzed blood concentrates, decreasing postoperative pain in 1, 2, 3, and 7 days and reducing trismus up to the inflammatory peak compared to blood clots. Only two studies had a low risk of bias.

CONCLUSIONS

Based on very low certainty of evidence, using concentrates seemed efficient compared to blood clots in reducing pain and trismus after mandibular third molar surgeries. A-PRF decreased postoperative pain throughout the evaluated time and trismus during the acute inflammatory peak.

CLINICAL RELEVANCE

A-PRF after mandibular third molar extractions performed better among the analyzed blood concentrates and seemed efficient in improving postoperative quality by decreasing inflammatory signs and symptoms.

del Nido versus blood cardioplegia in adult cardiac surgery: a meta-analysis

AIMS

Initially developed for myocardial protection in immature cardiomyocytes, del Nido cardioplegia has been increasingly used over the past decade in adult patients. Our aim is to analyse the results from randomized controlled trials and observational studies comparing early mortality and postoperative troponin release in patients who underwent cardiac surgery using del Nido solution and blood cardioplegia.

METHODS

A literature search was performed through three online databases between January 2010 and August 2022. Clinical studies providing early mortality and/or postoperative troponin evaluation were included. A random-effects meta-analysis with a generalized linear mixed model, incorporating random study effects, was implemented to compare the two groups.

RESULTS

Forty-two articles were included in the final analysis for a total of 11 832 patients, 5926 of whom received del Nido solution and 5906 received blood cardioplegia. del Nido and blood cardioplegia populations had comparable age, gender distribution, history of hypertension and diabetes mellitus. There was no difference in early mortality between the two groups. There was a trend towards lower 24 h [mean difference -0.20; 95% confidence interval (CI) -0.40 to 0.00; I2 = 89%; P = 0.056] and lower peak postoperative troponin levels (mean difference -0.10; 95% CI -0.21 to 0.01; I2 = 0.87; P = 0.087) in the del Nido group.

CONCLUSION

del Nido cardioplegia can be safely used in adult cardiac surgery. The use of del Nido solution was associated with similar results in terms of early mortality and postoperative troponin release when compared with blood cardioplegia myocardial protection.

Janus Kinase Inhibitors for Alopecia Areata: A Systematic Review and Meta-Analysis

Importance

Alopecia areata (AA) is a common chronic tissue-specific autoimmune disease. Several studies have reported outcomes of Janus kinase (JAK) inhibitors for treating AA, but limited evidence has emerged.

Objective

To evaluate the effectiveness and safety associated with JAK inhibitors for AA.

Data Sources

MEDLINE, Embase, and CENTRAL (Cochrane Central Register of Controlled Trials) were searched from inception until August 2022.

Study Selection

Only randomized clinical trials (RCTs) were included. Pairs of reviewers independently and in duplicate selected the studies.

Data Extraction and Synthesis

Hartung-Knapp-Sidik-Jonkman random-effects models were used for meta-analysis. Certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. This study is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

The primary outcomes of interest were (1) proportion of patients who achieved 30%, 50%, and 90% improvement in Severity of Alopecia Tool (SALT) score from baseline, (2) change from baseline SALT score, and (3) treatment-related adverse event (AE).

Results

Seven RCTs with 1710 patients (1083 females [63.3%]; mean [SD] age range, 36.3 [10.4] to 69.7 [16.2] years) were eligible and included in the study. JAK inhibitors were associated with more patients achieving 50% improvement (odds ratio [OR], 5.28 [95% CI, 1.69-16.46]; GRADE assessment: low certainty) and 90% improvement (OR, 8.15 [95% CI, 4.42-15.03]; GRADE assessment: low certainty) in SALT score from baseline compared with placebo. JAK inhibitors were associated with more lowered SALT scores from the baseline compared with placebo (mean difference [MD], -34.52 [95% CI, -37.80 to -31.24]; GRADE assessment: moderate certainty), and JAK inhibitors were not associated with more treatment-related AEs (relative risk [RR], 1.25 [95% CI, 1.00-1.57]; GRADE assessment: high certainty) compared with placebo. High certainty of evidence showed that JAK inhibitors may not be associated with more severe AEs compared with placebo (RR, 0.77; 95% CI, 0.41-1.43). The subgroup analysis showed that oral JAK inhibitors were more efficient than placebo (change from baseline SALT scores: MD, -36.80; 95% CI, -39.57 to -34.02), and no difference was found between external JAK inhibitors and placebo (change from baseline SALT scores: MD, -0.40; 95% CI, -11.30 to 10.50).

Conclusions and Relevance

Results of this systematic review and meta-analysis suggest that JAK inhibitors, compared with placebo, were associated with hair regrowth and that the outcome of oral JAK inhibitors was better than the external route of administration. Although the safety and tolerability of JAK inhibitors were acceptable, longer RCTs are needed to further assess the effectiveness and safety of these treatments for AA.

Cardiotoxicity of immune checkpoint inhibitors: A frequency network meta-analysis

Immune checkpoint inhibitors (ICIs) in combination withother anti-cancer treatments have been approved for a variety of cancers. While the difference in the incidence of cardiovascular adverse events has not been fully investigated. We aimed to assess the the differences in cardiotoxicity among cancer patients receiving different ICI therapies. PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov. websites were searched for all randomized controlled trials (RCTs) of ICI. The primary outcomes were any grade cardiotoxicity and Grade 3-5 cardiotoxicity, the secondary outcomes were any grade myocarditis and Grade 3-5 myocarditis, with sub-analyses based on cancer type and does of ICI. A systematic review and frequency network meta-analysis were then performed for cardiotoxicity events. 91 RCTs (n=52247) involving 12 treatment arms were finally included. We observed that PD-L1 + CTLA-4 had the highest risk among all therapies inducing any grade cardiotoxicity, and the differences were significant except PD-1 + CTLA-4, PD-1 + TTD and PD-L1 + TTD. In addition, CTLA-4 had a higher risk of Grade 3-5 cardiotoxicity than PD-1 and anit-PD-L1. For Grade 1-5 myocarditis and Grade 3-5 myocarditis, no significant difference was found among differences therapies. No differences were observed in subgroup analyses according to does and cancer type. There were differences in the incidence of cardiotoxicity among different ICI therapies. For ICI monotherapy, CTLA-4 may be linked to Grade 3-5 cardiotoxicity than PD-1 or PD-L1. For dual therapy, the cardiotoxicity of dual ICI therapy seems to be higher than that of chemotherapy or targeted therapy.