Meta-analysis: Key features, potentials and misunderstandings

Effects of resveratrol on biochemical and structural outcomes in osteoarthritis: A systematic review and meta-analysis of preclinical studies

Background and objective

Osteoarthritis (OA) is the most common age-related disease of joints with increasing global prevalence. Persistent inflammation within the joint space is speculated to be the cause of OA. Resveratrol is an anti-inflammatory and antioxidant compound which can influence cartilage metabolism through multiple signalling pathways. This systematic review and meta-analysis aimed to summarize the therapeutic effects of resveratrol in animal models of OA.

Methods

A comprehensive literature search was performed using PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, China Wanfang and VIP databases in May 2023. Studies on the effects of resveratrol in animal models of OA written in English or Mandarin, published from the inception of databases until the date of the search were considered.

Results

Fifteen eligibility studies were included and analysed. Resveratrol was shown to inhibit the secretion of interleukin-1β, tumour necrosis factor-α, interleukin-6, nitric oxide, and apoptosis of articular chondrocytes. Joint structure as indicated by Mankin scores was restored with resveratrol in animal OA models.

Conclusion

Resveratrol is a potential therapeutic agent for OA based on animal studies. Further evidence from well-planned human studies would be required to validate its clinical efficacies.

Safety and efficacy of COVID-19 vaccines: A systematic review and meta-analysis of controlled and randomized clinical trials

Vaccines against coronavirus disease 2019 (COVID-19) have been discovered within a very small duration of time as compared to the traditional way for the development of vaccines, which raised the question about the safety and efficacy of the approved vaccines. The purpose of this study is to look at the effectiveness and safety of vaccine platforms against the incidence of COVID-19. The literature search was performed on PubMed/Medline, Cochrane, and clinical trials.gov databases for studies published between 1 January 2020 and 19 February 2022. Preferred Reporting Items for Systemic Review and Meta-Analysis Statement guidelines were followed. Among 284 articles received by keywords, a total of 11 studies were eligible according to the inclusion and exclusion criteria (studies in special populations, e.g., pregnant women, paediatric patients, editorials, case reports, review articles, preclinical and in vitro studies) of the study. A total of 247,186 participants were considered for randomisation at baseline, among them, 129,572 (52.42%) were provided with vaccine (Intervention group) and 117,614 (47.58%) with the placebo (Control group). A pooled fold change estimation of 0.19 (95% CI: 0.12-0.31, p < 0.0001) showed significant protection against the incidence of COVID-19 in the vaccines received group versus the placebo group. mRNA based, inactivated vaccines and non-replicating viral vector-based vaccines showed significantly protection against the incidence of COVID-19 compared to placebo with pooled fold change estimation was 0.08 (95% CI: 0.06-0.10), 0.20 (95% CI: 0.14-0.29) and 0.36 (95% CI: 0.28-0.46), respectively. Injection site discomfort and fatigue were the most common side effect observed in mRNA, non-replicating viral vector, inactivated, and protein subunit-based vaccines. All the approved vaccines were found safe and efficacious but mRNA-based vaccines were found to be more efficacious against SARS-CoV-2 than other platforms.

Transcranial Alternating Current Stimulation to Modulate Alpha Activity: A Systematic Review

BACKGROUND

Transcranial alternating current stimulation (tACS) has been one of numerous investigation methods used for their potential to modulate brain oscillations; however, such investigations have given contradictory results and a lack of standardization.

OBJECTIVES

In this systematic review, we aimed to assess the potential of tACS to modulate alpha spectral power. The secondary outcome was the identification of tACS methodologic key parameters, adverse effects, and sensations.

MATERIALS AND METHODS

Studies in healthy adults who were receiving active and sham tACS intervention or any differential condition were included. The main outcome assessed was the increase/decrease of alpha spectral power through either electroencephalography or magnetoencephalography. Secondary outcomes were methodologic parameters, sensation reporting, and adverse effects. Risks of bias and the study quality were assessed with the Cochrane assessment tool.

RESULTS

We obtained 1429 references, and 20 met the selection criteria. A statistically significant alpha-power increase was observed in nine studies using continuous tACS stimulation and two using intermittent tACS stimulation set at a frequency within the alpha range. A statistically significant alpha-power increase was observed in three more studies using a stimulation frequency outside the alpha range. Heterogeneity among stimulation parameters was recognized. Reported adverse effects were mild. The implementation of double blind was identified as challenging using tACS, in part owing to electrical artifacts generated by stimulation on the recorded signal.

CONCLUSIONS

Most assessed studies reported that tACS has the potential to modulate brain alpha power. The optimization of this noninvasive brain stimulation method is of interest mostly for its potential clinical applications with neurological conditions associated with perturbations in alpha brain activity. However, more research efforts are needed to standardize optimal parameters to achieve lasting modulation effects, develop methodologic alternatives to reduce experimental bias, and improve the quality of studies using tACS to modulate brain activity.

Clinical outcomes in the surgical management of ankle fractures: A systematic review and meta-analysis of fibular intramedullary nail fixation vs. open reduction and internal fixation in randomized controlled trials

BACKGROUND

What level I evidence exists to support the use of FNF for surgical management of ankle fractures in high risk patients? The purpose of this study was to compare clinical outcomes following fibular intramedullary nail fixation (FNF) and open reduction and internal fixation (ORIF) of ankle fractures.

METHODS

A systematic review of the current literature was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Certainty of evidence reported according to GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Our primary hypothesis was that patients undergoing FNF procedures to manage an ankle fracture would have significantly higher patient reported outcome scores (PROs) than patients undergoing ORIF. Primary study outcome measures were validated PROs. Secondary outcome measures included complication rate, secondary surgery rate, and bony union.

RESULTS

The primary outcome analysis revealed no evidence of a significant effect difference on Olerud and Molander Ankle Score (OMAS) PRO and no evidence of statistical heterogeneity. Secondary outcome analysis revealed a significant 0.30 (0.12-0.74 95CI) relative risk reduction for complications in FNF (P = 0.008). No evidence of an effect difference for bony union. The GRADE certainty of the evidence was rated as low for bone union. No evidence of reporting bias was appreciated. Sensitivity analyses did not significantly alter effect estimates.

CONCLUSION

This systematic review and meta-analysis restricted to evidence derived from RCTs revealed that the quality of evidence is reasonably strong and likely sufficient to conclude: (1) there is likely no clinically important difference between FNF and ORIF up to 12 months post-operatively, as defined by OMS (moderate certainty); (2) surgeons may reasonably expect reduced complications in 14 out of every 100 patients treated with FNF (moderate certainty); (3) there is likely no difference in bony union (low certainty). Future studies should investigate more patient-centered outcomes and if short-term findings are durable over time if these findings apply to lower risk populations.

LEVEL OF EVIDENCE

Systematic review and meta-analysis of level I evidence.

Effect of corticosteroid therapy on mortality in COVID-19 patients-A systematic review and meta-analysis

The effect of corticosteroid therapy is still controversial on prevention of mortality in coronavirus disease‐2019 (COVID‐19). The objective of this study is to investigate the effect of corticosteroids on mortality. This systematic review was performed as per preferred reporting items for systematic reviews and meta‐analyses guidelines. A systematic search was performed at different databases namely Medline/PubMed, Cochrane and Google scholar on 10 February 2022. A pooled estimate for effect of corticosteroid therapy on mortality was calculated as outcome of study. Risk bias analysis and Newcastle Ottawa Scale were used to assess the quality of randomized control trial (RCT) and cohort studies, respectively. Cochran's Q test and the I² statistic were conducted for heterogeneity and accordingly study model was applied. A total 43 studies were included, having sample size of 96,852 patients. Amongst them, 19,426 and 77,426 patients received corticosteroid therapy (intervention group) or standard treatment without corticosteroid (control group), respectively. Mortality observed in the intervention and control group was 14.2% (2749) and 7.1% (5459), respectively. The pooled estimate 2.173 (95% CI: 2.0690–2.2820) showed significantly increased mortality in intervention as compared to control. The pooled estimate of methyprednisolone 1.206 (95% CI: 1.0770–1.3500) showed significantly increased mortality while the pooled estimate of dexamethasone 1.040 (95% CI: 0.9459–1.1440) showed insignificantly increased mortality as compared to control. In conclusion, corticosteroid therapy produced a negative prognosis as depicted by increased mortality among COVID‐19 patients. The possible reasons might be delay in virus clearance and secondary infections due to corticosteroids initiated at high dose in the early stage of infection.

The Effect of Peer Support in Diabetes Self-Management Education on Glycemic Control in Patients with Type 2 Diabetes: A Meta-Analysis

OBJECTIVES

Diabetes self-management education (DSME) programs are a strategy to maintain healthy behaviors. Nevertheless, limited evidence has been reported from systematic evaluations of the effects of DSME integrated with peer support on glycemic control. This study aimed to review the effectiveness of DSME interventions integrated with peer support on glycemic control in patients with type 2 diabetes.

METHODS

A systematic search was carried out in electronic databases, including PubMed, Cochrane Library, ProQuest, SpringerLink, ScienceDirect, Scopus, and Google Scholar, for English-language articles published from 2005 until 2020. The effect size was estimated as the standard mean difference (SMD). The Cochrane Collaboration’s Risk of Bias tool was employed to assess the risk of bias.

RESULTS

Twelve studies were included in this study. DSME integrated with peer support effectively reduced glycated hemoglobin A1c (HbA1c) levels, with a statistically significant effect (SMD, -0.41; 95% confidence interval [CI], -0.69 to -0.13; p<0.001). Programs with a sample size <100 (SMD, -0.45; 95% CI, -0.79 to -0.11; p=0.009), duration of intervention ≤6 months (SMD, -0.52; 95% CI, -0.96 to -0.07; p=0.020), baseline HbA1c <8.5% (SMD, -0.42; 95% CI, -0.77 to -0.07; p=0.020), delivery by group (SMD, -0.28; 95% CI, -0.51 to -0.06; p=0.010), and high frequency of contact (SMD, -0.29; 95% CI, -0.48 to -0.10; p=0.003) had statistically significant effects on reducing HbA1c levels in patients with type 2 diabetes.

CONCLUSIONS

DSME integrated with peer support effectively enhances glycemic control in patients with type 2 diabetes. Programs with smaller participants groups, shorter interventions, weekly meetings, and closer group sessions improved glycemic control in patients with type 2 diabetes.

Corticosteroid use in COVID-19 patients: a systematic review and meta-analysis on clinical outcomes

BACKGROUND

In the current SARS-CoV-2 pandemic, there has been worldwide debate on the use of corticosteroids in COVID-19. In the recent RECOVERY trial, evaluating the effect of dexamethasone, a reduced 28-day mortality in patients requiring oxygen therapy or mechanical ventilation was shown. Their results have led to considering amendments in guidelines or actually already recommending corticosteroids in COVID-19. However, the effectiveness and safety of corticosteroids still remain uncertain, and reliable data to further shed light on the benefit and harm are needed.

OBJECTIVES

The aim of this systematic review and meta-analysis was to evaluate the effectiveness and safety of corticosteroids in COVID-19.

METHODS

A systematic literature search of RCTS and observational studies on adult patients was performed across Medline/PubMed, Embase and Web of Science from December 1, 2019, until October 1, 2020, according to the PRISMA guidelines. Primary outcomes were short-term mortality and viral clearance (based on RT-PCR in respiratory specimens). Secondary outcomes were: need for mechanical ventilation, need for other oxygen therapy, length of hospital stay and secondary infections.

RESULTS

Forty-four studies were included, covering 20.197 patients. In twenty-two studies, the effect of corticosteroid use on mortality was quantified. The overall pooled estimate (observational studies and RCTs) showed a significant reduced mortality in the corticosteroid group (OR 0.72 (95%CI 0.57-0.87). Furthermore, viral clearance time ranged from 10 to 29 days in the corticosteroid group and from 8 to 24 days in the standard of care group. Fourteen studies reported a positive effect of corticosteroids on need for and duration of mechanical ventilation. A trend toward more infections and antibiotic use was present.

CONCLUSIONS

Our findings from both observational studies and RCTs confirm a beneficial effect of corticosteroids on short-term mortality and a reduction in need for mechanical ventilation. And although data in the studies were too sparse to draw any firm conclusions, there might be a signal of delayed viral clearance and an increase in secondary infections.

Importance of Systematic Reviews and Meta-analyses of Animal Studies: Challenges for Animal-to-Human Translation

Results of animal experiments are used for understanding the pathophysiology of diseases, assessing safety and efficacy of newly developed drugs, and monitoring environmental health hazards among others. Systematic reviews and meta-analyses of animal data are important tools to condense animal evidence and translate the data into practical clinical applications. Such studies are conducted to explore heterogeneity, to generate new hypotheses about pathophysiology and treatment, to design new clinical trial modalities, and to test the efficacy and the safety of the various interventions. Here, we provide an overview regarding the importance of systematic reviews and meta-analyses of animal data and discuss common challenges and their potential solutions. Current evidence highlights various problems and challenges that surround these issues, including lack of generalizability of data obtained from animal models, failure in translating data obtained from animals to humans, poor experimental design and the reporting of the animal studies, heterogeneity of the data collected, and methodologic weaknesses of animal systematic reviews and meta-analyses. Systematic reviews and meta-analyses of animal studies can catalyze translational processes more effectively if they focus on a well-defined hypothesis along with addressing clear inclusion and exclusion criteria, publication bias, heterogeneity of the data, and a coherent and well-balanced assessment of studies' quality.

Acute kidney injury and kidney replacement therapy in COVID-19: a systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) can affect hospitalized patients with coronavirus disease 2019 (COVID-19), with estimates ranging between 0.5% and 40%. We performed a systematic review and meta-analysis of studies reporting incidence, mortality and risk factors for AKI in hospitalized COVID-19 patients.

METHODS

We systematically searched 11 electronic databases until 29 May 2020 for studies in English reporting original data on AKI and kidney replacement therapy (KRT) in hospitalized COVID-19 patients. Incidences of AKI and KRT and risk ratios for mortality associated with AKI were pooled using generalized linear mixed and random-effects models. Potential risk factors for AKI were assessed using meta-regression. Incidences were stratified by geographic location and disease severity.

RESULTS

A total of 3042 articles were identified, of which 142 studies were included, with 49 048 hospitalized COVID-19 patients including 5152 AKI events. The risk of bias of included studies was generally low. The pooled incidence of AKI was 28.6% [95% confidence interval (CI) 19.8-39.5] among hospitalized COVID-19 patients from the USA and Europe (20 studies) and 5.5% (95% CI 4.1-7.4) among patients from China (62 studies), whereas the pooled incidence of KRT was 7.7% (95% CI 5.1-11.4; 18 studies) and 2.2% (95% CI 1.5-3.3; 52 studies), respectively. Among patients admitted to the intensive care unit, the incidence of KRT was 20.6% (95% CI 15.7-26.7; 38 studies). Meta-regression analyses showed that age, male sex, cardiovascular disease, diabetes mellitus, hypertension and chronic kidney disease were associated with the occurrence of AKI; in itself, AKI was associated with an increased risk of mortality, with a pooled risk ratio of 4.6 (95% CI 3.3-6.5).

CONCLUSIONS

AKI and KRT are common events in hospitalized COVID-19 patients, with estimates varying across geographic locations. Additional studies are needed to better understand the underlying mechanisms and optimal treatment of AKI in these patients.

Clinical characteristics of patients with ROS1 gene rearrangement in non-small cell lung cancer: a meta-analysis

BACKGROUND

ROS1 gene rearrangement has been reported in several types of cancers, including non-small cell lung cancer (NSCLC). It is reported that tyrosine kinase inhibitors are effective in the treatment of ROS1-rearranged NSCLC. Therefore, the identification of ROS1 rearrangement can be used as potential therapeutic target in lung cancer. Epidemiological data indicates that ROS1 gene rearrangement occurs in approximately 1-2% of NSCLC patients. The small sample sizes of the existing associated studies only represent the characteristics of patients in specific regions or countries, and there is still no latest statistical analysis on ROS1 gene rearrangement anywhere in the world.

METHODS

We conducted a systematic search of the PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CBM, CNKI, Wanfang, and VIP databases to identify studies on ROS1 gene rearrangement in NSCLC patients from January 1, 2015 to October 27, 2019. We conducted a meta-analysis to investigate the relationship between ROS1 gene rearrangement and clinical characteristics of NSCLC patients. The four clinical features are as follows: gender, smoking status, pathological type, and lung cancer stage.

RESULTS

Thirty-nine studies constituting of 25,055 NSCLC patients were eligible for inclusion in this meta-analysis. A prominently higher rate of ROS1 gene rearrangement was observed in female NSCLC patients (OR =1.94, 95% CI: 1.62-2.32%, P<0.05), patients with no smoking history (OR =2.82, 95% CI: 2.24-3.55%, P<0.05), patients with adenocarcinoma (OR =1.55, 95% CI: 1.14-2.11%, P<0.05), and patients with stage III-IV disease (OR =1.50, 95% CI: 1.15-1.94%, P<0.05). Our meta-analysis also showed that the prevalence of ROS1 rearrangement in adenocarcinoma was 2.49% (95% CI: 1.92-3.11%), while it was lower in non-adenocarcinoma patients (1.37%).

CONCLUSIONS

ROS1 gene rearrangement was more predominant in female patients, patients without smoking history, patients with adenocarcinoma and patients with advanced-stage disease (stages III to IV).