Exploring heterogeneity in meta-analysis: Meta-regression analysis

Comparative efficacy of intratympanic gentamicin and intratympanic corticosteroid in the treatment of Meniere's disease: a systematic review and meta-analysis

Purpose

We aimed to evaluate the efficacy of gentamicin compared to corticosteroids for the treatment of Meniere's disease.

Methods

An extensive search was conducted in PubMed, Embase, and Web of Science until May 2024. For continuous outcomes, pooled effect estimates were determined by calculating the weighted mean difference (WMD), while for binary outcomes, the risk ratio (RR) was used, each accompanied by their respective 95% confidence intervals (CIs). Heterogeneity among the studies was assessed using Cochran's I 2 and Q statistics.

Results

A total of 12 studies were selected, involving 694 patients. Our analysis found that the gentamicin group demonstrates superior vertigo control rates compared to the corticosteroid group (RR: 1.36, 95% CI: 1.13 to 1.65, p < 0.001). In subgroup analysis, the gentamicin group showed a higher vertigo control rates at 6 months compared to the corticosteroid group (RR: 1.69, 95% CI: 1.28 to 2.24, p < 0.001); however, there was no statistically significant difference between the two groups at 12 months (RR: 1.48, 95% CI: 0.88 to 2.49, p = 0.14). Regarding changes in pure tone average, the corticosteroid group was superior to the gentamicin group (WMD: 4.41, 95% CI: 3.31 to 5.52, p < 0.001).

Conclusion

Our study suggests that the intratympanic gentamicin group achieves higher vertigo control rates, whereas the corticosteroid group demonstrates better improvement in pure tone averages. However, the high heterogeneity in vertigo control rates warrants caution. Larger sample-sized randomized controlled trials are needed to further validate these findings.

Bayesian networks in modeling leucocyte interplay following brain irradiation: A comprehensive framework

BACKGROUND AND OBJECTIVE

Understanding the intricate interactions among leucocyte subpopulations following radiotherapy is crucial for advancing cancer research and immunology. Recently, interest in recent radiotherapy modalities, such as protons, has increased. Herein, we present a framework utilizing Bayesian networks to uncover these complex relationships via an illustrative example of brain irradiation in rodents.

METHODS

We utilized data from 96 healthy C57BL/6 adult mice subjected to either X-ray or proton brain irradiation. Leucocyte subpopulations in the blood collected 12 h after the final irradiated fraction were quantified. We employed Bayesian networks to detect causal interplay between physiological parameters, radiation variables and circulating leucocytes. The causal structure was learned via the use of the Bayesian information criterion as a scored criterion. Parameter estimation was performed to quantify the strength of the identified causal relationships. Cross-validation was used to validate our Bayesian network model's performance.

RESULTS

In the X-ray model, we discovered previously undisclosed interactions between NK-cells and neutrophils, and between monocytes and T-CD4+ cells. The proton model revealed an interplay involving T-CD4+ cells and neutrophils. Both X-rays and protons led to heightened interactions between T-CD8+ cells and B cells, indicating their significant role in orchestrating immune responses. Additionally, the proton model displayed strengthened interactions between T-CD4+ and T-CD8+ cells, emphasizing a dynamic and coordinated immune response post-irradiation. Cross-validation results demonstrated the robustness of the Bayesian network model in explaining data uncertainty.

CONCLUSION

The use of Bayesian networks as tools for causal structure discovery has revealed novel insights into the dynamics of immune responses to radiation exposure.

Dental caries and developmental defects of enamel in cerebral palsy: A meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to compare the occurrence of dental caries and developmental defects of enamel (DDE) in individuals with and without cerebral palsy (CP).

MATERIALS AND METHODS

We conducted searches across five databases and the grey literature. Data were organized using EndNote 20. Reporting followed the MOOSE checklist. A random-effects model meta-analyses were conducted using RStudio, presenting results as mean difference (MD), odds ratio (OR), and 95% confidence interval (CI). The risk of bias of studies was analyzed using the Newcastle-Ottawa Scale, and the certainty of evidence was assessed using GRADE.

RESULTS

Among 1336 identified records, 25 studies involving 59,997 participants (mean age: 11.1 years) were included. Data of 12 were pooled into meta-analyses. No significant differences were found between CP and non-CP individuals across indices: DMFT (k = 7) (MD = 0.31; 95% CI [-0.42-1.05]), dmft (k = 4) (MD = 0.31; 95% CI [-0.50-1.14]), DMFS (k = 2) (MD = -0.61; 95% CI [-20.56-19.33]), dmfs (k = 3) (MD = 0.54; 95% CI [-1.09-2.17]), and DDE (k = 3) (OR = 0.80, 95% CI [0.09-7.31]). The certainty of evidence was very low.

CONCLUSION

Individuals with CP do not appear to differ significantly from those without CP in terms of dental caries experience and DDE.

Emergent methods for inactivation of Cronobacter sakazakii in foods: A systematic review and meta-analysis

Cronobacter sakazakii is a potentially pathogenic bacterium that is resistant to osmotic stress and low aw, and capable of persisting in a desiccated state in powdered infant milks. It is widespread in the environment and present in various products. Despite the low incidence of cases, its high mortality rates of 40 to 80 % amongst neonates make it a microorganism of public health interest. This current study performed a comparative assessment between current reduction methods applied for C. sakazakii in various food matrices, indicating tendencies and relevant parameters for process optimization. A systematic review and meta-analysis were conducted, qualitatively identifying the main methods of inactivation and control, and quantitatively evaluating the effect of treatment factors on the reduction response. Hierarchical clustering dendrograms led to conclusions on the efficiency of each treatment. Review of recent research trend identified a focus on the potential use of alternative treatments, with most studies related to non-thermal methods and dairy products. Using random-effects meta-analysis, a summary effect-size of 4-log was estimated; however, thermal methods and treatments on dairy matrices displayed wider dispersions - of τ2 = 8.1, compared with τ2 = 4.5 for vegetal matrices and τ2 = 4.0 for biofilms. Meta-analytical models indicated that factors such as chemical concentration, energy applied, and treatment time had a more significant impact on reduction than the increase in temperature. Non-thermal treatments, synergically associated with heat, and treatments on dairy matrices were found to be the most efficient.

A network meta-analysis comparative the efficacy of angiotensin-converting enzyme inhibitors and calcium channel blockers in hypertension

BACKGROUND

Currently, most studies primarily focus on directly comparing the efficacy and safety of angiotensin-converting enzyme inhibitors (ACEIs) and calcium channel blockers (CCBs), the two major classes of antihypertensive drugs. Moreover, the majority of studies are based on randomized controlled trials and traditional meta-analyses, with few exploring the efficacy and safety comparisons among various members of ACEIs and CCBs.

METHODS

ACEIs and CCB were searched for in randomized controlled trials in CNKI, Wanfang, VIP, China Biology Medicine Disc (Si-noMed), PubMed, EMbase, and Cochrane Library databases. The search can be conducted till November 2022. Stata software (version 16.0) and R 4.1.3 was used for statistical analysis and graphics plotting, applying mvmeta, gemtc, and its packages. Meta-regression analysis was used to explore the inconsistencies of the studies.

RESULTS

In 73 trials involving 33 different drugs, a total of 9176 hypertensive patients were included in the analysis, with 4623 in the intervention group and 4553 in the control group. The results of the analysis showed that, according to the SUCRA ranking, felodipine (MD = -12.34, 95% CI: -17.8 to -6.82) was the drug most likely to be the best intervention for systolic blood pressure, while nitrendipine (MD = -8.01, 95% CI: -11.71 to -4.18) was the drug most likely to be the best intervention for diastolic blood pressure. Regarding adverse drug reactions, nifedipine (OR = 0.32, 95% CI: 0.14-0.74) was the drug most likely to be the safest.

CONCLUSION

The research findings indicate that nifedipine is the optimal intervention for reducing systolic blood pressure in hypertensive patients, nitrendipine is the optimal intervention for reducing diastolic blood pressure in hypertensive patients, and felodipine is the optimal intervention for safety.

Pearls of meta-analyses and systematic review in scientific evidence

Scientific evidence develops bit by bit from case reports, case series; to larger case-control, case-cohort; and further escalate to randomized controlled trials. This echoed the importance of continue publishing World journal of Clinical Cases, where novel and advancing discoveries start from a single case. In contrast, at the other end of the realm of evidence synthesis, systematic review and meta-analysis represent distinct yet interconnected processes. Butorphanol in epidural labor analgesia has long been studied since 1989, and with 70 publications from MEDLINE searches. However, there was no meta-analysis, nor any systematic review published so far. The latest in-press article published by Tang et al. on the protocol for the systematic review and meta-analysis on the safety and effectiveness of butorphanol in epidural labor analgesia is encouraging. We believe the findings of this study will be valuable for clinical practice as well as for future research.

Importance of well-designed meta-analyses in assessing medical and surgical treatments

When evaluating the efficacy of medical or surgical treatments, the most robust study design is often considered to be the high-quality randomized clinical trial (RCT). However, the true answer lies in the meta-analysis of high-quality RCTs. While RCTs have their merits, meta-analyses possess two crucial qualities that make them superior: Generalizability and the ability to verify replicability across different trials. A well-designed meta-analysis, defined here as a systematic review that pools data, holds significant advantages over individual RCTs. Retrospective and observational surgical research is prone to biases that are not mutually offsetting; instead, they accumulate. Selection bias, transfer bias, and assessment bias all taint retrospective studies more than randomized trials, making the novel treatment appear more effective than it truly is. Pooling studies suffering from these limitations in a meta-analysis amplifies these biases, causing an overestimation of treatment benefits. This becomes particularly concerning when the treatment itself carries substantial risks, as is often the case in surgical journals. The consequences can result in harm or even death for patients. While a well-designed meta-analysis is the best tool for assessing medical and surgical treatments, a weak meta-analysis amplifies biases and promotes flawed data. Thoughtful readers must become proficient in honing their methodological toolkits, delving deeper into topics like heterogeneity and publication bias. It is essential to avoid wasting time on meta-analyses drawing data from retrospective or observational research regarding surgical treatments.

Shift work and menstruation: A meta-analysis study

Background

Shift work is a potential risk factor for women's reproductive health. Evidence suggests that shift work is associated with menstrual disorders, reproductive disturbances, and adverse pregnancy outcomes. However, previous studies did not systematically examine the results of menstrual irregularities, dysmenorrhea, and early menopause at the same time.

Objective

To determine the relationship between shift work and women's menstrual characteristics (e.g., irregular menstruation, dysmenorrhea, and early menopause).

Methods

Four databases (PubMed, Embase, Cochrane, and Web of Science) were searched up to December 2022. The study characteristics and risk assessment values of the literature were extracted from 21 studies that met the criteria. Odds ratios (ORs), relative risks (RRs), hazard ratios (HRs), and 95% confidence intervals (CIs) were calculated to assess the relationship between shift work exposure and menstruation. The included studies were evaluated for heterogeneity, publication bias, sensitivity analysis, and subgroup analysis.

Results

A total of 21 studies with 195,538 female participants, including 16 cross-sectional studies and 5 cohort studies, were included in this meta-analysis. According to the quality evaluation, the included research had high methodological quality. The overall ORs of shift work for the likelihood of irregular menstruation and dysmenorrhea were 1.30 (95% CI, 1.23-1.36) (I2 = 41.9%, P < 0.05) and 1.35 (95% CI, 1.04-1.75) (I2 = 73.0%, P < 0.05), respectively. There was a significant positive association between shift work and the risk of early menopause (HR = 1.09, 95% CI, 1.04-1.14), without significant heterogeneity (I2 = 0.0%, P > 0.05).

Conclusions

This meta-analysis indicated that shift workers have significantly higher odds of menstrual disorders, dysmenorrhea, and early menopause. This study focuses on female reproductive health and has broad implications for adjusting optimal working hours and shift schedules for female workers.

Diagnostic performance of noninvasive imaging using computed tomography, magnetic resonance imaging, and positron emission tomography for the detection of ovarian cancer: a meta-analysis

OBJECTIVE

The aim of this meta-analysis was to compare the diagnostic value of noninvasive imaging methods computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) in the detection of ovarian cancer (OC).

METHODS

PubMed, Embase, and Ovid were comprehensively searched from the date of inception to 31st, March, 2022. Pooled sensitivity, specificity, positive likelihood ratio (+ LR), negative likelihood ratio (- LR), diagnostic odds ratio (DOR), and area under the curve (AUC) of summary receiver operating characteristic (SROC) with their respective 95% confidence intervals (CIs) were calculated.

RESULTS

Sixty-one articles including 4284 patients met the inclusion criteria of this study. Pooled estimates of sensitivity, specificity, and AUC of SROC with respective 95% CIs of CT on patient level were 0.83 (0.73, 0.90), 0.69 (0.54, 0.81), and 0.84 (0.80, 0.87). The overall sensitivity, specificity, SROC value with respective 95% CIs of MRI were 0.95 (0.91, 0.97),0.81 (0.76, 0.85), and 0.90 (0.87, 0.92) on patient level. Pooled estimates of sensitivity, specificity, SROC value of PET/CT on patient level were 0.92 (0.88, 0.94), 0.88 (0.83, 0.92), and 0.96 (0.94, 0.97).

CONCLUSION

Noninvasive imaging modalities including CT, MRI, PET (PET/CT, PET/MRI) yielded favorable diagnostic performance in the detection of OC. Hybrid implement of different tools (PET/MRI) is more accurate for identifying metastatic OC.

Association of reduced glutathione levels with Plasmodium falciparum and Plasmodium vivax malaria: a systematic review and meta-analysis

Reduced glutathione (GSH) is a crucial antioxidant with recognized roles in malaria pathogenesis and host response. Despite its importance, reports on the association of GSH with malaria are inconsistent. Therefore, this systematic review and meta-analysis investigated the differences in GSH levels in relation to Plasmodium infection. A comprehensive literature search of six electronic databases (Embase, MEDLINE, Ovid, PubMed, Scopus, and ProQuest) was conducted. Of the 2158 initially identified records, 18 met the eligibility criteria. The majority of studies reported a significant decrease in GSH levels in malaria patients compared with uninfected controls, and this was confirmed by meta-analysis (P < 0.01, Hedges g: - 1.47, 95% confidence interval [CI] - 2.48 to - 0.46, I2: 99.12%, 17 studies). Additionally, there was no significant difference in GSH levels between Plasmodium falciparum malaria and P. vivax malaria (P = 0.80, Hedges g:  0.11, 95% CI - 0.76 to 0.98, I2: 93.23%, three studies). Similarly, no significant variation was observed between symptomatic and asymptomatic malaria cases (P = 0.78, Hedges g: 0.06, 95% CI - 0.34 to 0.46, I2: 48.07%, two studies). In conclusion, although GSH levels appear to be generally lower in malaria patients, further detailed studies are necessary to fully elucidate this complex relationship.

Factors Associated With Delirium in Children: A Systematic Review and Meta-Analysis

OBJECTIVES

Pediatric delirium (PD) is a neuropsychiatric syndrome caused by a complex interplay between predisposing factors (e.g., age, cognitive impairment), acute illness, and environmental triggers. PD is associated with substantial morbidity and mortality. The objective of this study is to systematically review and evaluate factors associated with PD in hospitalized pediatric patients.

DATA SOURCES

A systematic search of PubMed, Embase, Ovid Medline, Web- of-Science, Cochrane, CIHNAL, and Google Scholar databases was conducted for relevant studies (1990-2022).

STUDY SELECTION

We included studies that compared pediatric patients with and without delirium. Reviews, editorials, congress abstracts, or studies that did not report factors for PD were excluded. No restrictions were imposed on language.

DATA EXTRACTION

Title and abstract were independently screened by two reviewers. Individual characteristics, study design, and outcomes were independently extracted.

DATA SYNTHESIS

Categorical dichotomous data were summarized across groups using Mantel-Haenszel odds ratios (ORs) with 95% 95% CIs. Either fixed-effect or random effects models were used as indicated by the results of a heterogeneity test. Of 1,846 abstracts, 24 studies were included. We identified 54 factors studied in univariate analyses, and 27 of these were associated with PD in multivariable analyses. In pooled analyses, greater odds of PD were associated with developmental delay (OR 3.98; 95% CI 1.54-10.26), need for mechanical ventilation (OR 6.02; 95% CI 4.43-8.19), use of physical restraints (OR 4.67; 95% CI 1.82-11.96), and receipt of either benzodiazepines (OR 4.10; 95% CI 2.48-6.80), opiates (OR 2.88; 95% CI 1.89-4.37), steroids (OR 2.02; 95% CI 1.47-2.77), or vasoactive medication (OR 3.68; 95% CI 1.17-11.60).

CONCLUSIONS

In this meta-analysis, we identified seven factors associated with greater odds of developing delirium during pediatric critical illness.

Treatment failure and associated factors among people living with HIV on highly active antiretroviral therapy in mainland China: A systematic review and meta-analysis

OBJECTIVE

Reducing the prevalence of treatment failure among people living with HIV (PLHIV) on highly active antiretroviral therapy (HAART) is crucial for improving individual health and reducing disease burden. This study aimed to assess existing evidence on treatment failure and its associated factors among PLHIV in mainland China.

METHODS

We conducted a comprehensive search of PubMed, Web of Science, Cochrane Library, WanFang, China National Knowledge Infrastructure, and SinoMed databases. Relevant studies on treatment failure among PLHIV in mainland China until September 2022 were searched, including cross-sectional, case-control, and cohort studies. The primary outcome was treatment failure, and secondary outcomes were the potential influencing factors of treatment failure. We performed a meta-analysis to pool each outcome of interest, including meta-regression, subgroup, publication bias, and sensitivity analyses.

RESULTS

A total of 81 studies were deemed eligible and included in the final meta-analysis. The pooled treatment failure prevalence among PLHIV in mainland China was 14.40% (95% confidence interval [CI]:12.30-16.63), of which the virological and immunological failure prevalence was 10.53% (95%CI:8.51-12.74) and 18.75% (95%CI:15.44-22.06), respectively. The treatment failure prevalence before and after 2016 was 18.96% (95%CI:13.84-24.67) and 13.19% (95%CI:10.91-15.64). Factors associated with treatment failure included good treatment adherence (odds ratio [OR] = 0.36, 95%CI:0.26-0.51), baseline CD4 counts>200 cells/μL (OR = 0.39, 95%CI:0.21-0.75), HAART regimens containing Tenofovir Disoproxil Fumarate (TDF) (OR = 0.70, 95%CI:0.54-0.92), WHO clinical stage III/IV (OR = 2.02, 95%CI:1.14-3.59) and age≥40 years (OR = 1.56, 95%CI:1.23-1.97).

CONCLUSION

The prevalence of treatment failure among PLHIV receiving HAART in mainland China was low and tended to decline. Poor adherence, low baseline CD4 count, HAART regimens without TDF, advanced clinical stage, and old age were contributing factors for treatment failure. Relevant intervention programs are needed with increasing treatment adherence through behavioral intervention or precise intervention targeting older adults.

Effects of exposure to environmental pollutants on mitochondrial DNA copy number: a meta-analysis

Exposure to environmental pollutants has been associated with alteration on relative levels of mitochondrial DNA copy number (mtDNAcn). However, the results obtained from epidemiological studies are inconsistent. This meta-analysis aimed to evaluate whether environmental pollutant exposure can modify the relative levels of mtDNAcn in humans. We performed a literature search using PubMed, Scopus, and Web of Science databases. We selected and reviewed original articles performed in humans that analyzed the relationship between environmental pollutant exposure and the relative levels of mtDNAcn; the selection of the included studies was based on inclusion and exclusion criteria. Only twenty-two studies fulfilled our inclusion criteria. A total of 6011 study participants were included in this systematic review and meta-analysis. We grouped the included studies into four main categories according to the type of environmental pollutant: (1) heavy metals, (2) polycyclic aromatic hydrocarbons (PAHs), (3) particulate matter (PM), and (4) cigarette smoking. Inconclusive results were observed in all categories; the pooled analysis shows a marginal increase of relative levels of mtDNAcn in response to environmental pollutant exposure. The trial sequential analysis and rate confidence in body evidence showed the need to perform new studies. Therefore, a large-scale cohort and mechanistic studies in this area are required to probe the possible use of relative levels of mtDNAcn as biomarkers linked to environmental pollution exposure.

Surgical Treatment of Primary Cardiac Tumors in Children Systematic Review and Meta-analysis

This systematic review sought to investigate the current evidence regarding surgical management of primary cardiac tumors in children. Twenty-four studies were deemed eligible, reporting on 713 pediatric patients. Cumulative 30-day mortality rate was 5.5% and 7.5% after surgery. It was revealed a statistically lower mortality rate in the group of patients below 1 year of age, justifying a more aggressive surgical approach for primary cardiac tumors, except for rhabdomyoma that can regress spontaneously.