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At least 415 records · Page 23Linked to original sources

Auditory brainstem response in the identification of cochlear synaptopathy in aged rodents: a systematic review with meta-analysis.

PURPOSE: This systematic review and meta-analysis evaluated the diagnostic performance of auditory brainstem response (ABR) for identifying age-related cochlear synaptopathies in rodents. METHOD: Following PRISMA guidelines, searches were conducted in PubMed/MEDLINE, Cochrane Library, Scopus, Embase, Web of Science, SciELO, LILACS, and gray literature. Studies evaluating CS in naturally aged rodents using short-latency auditory evoked potentials (AEPs) were included. Study selection, data extraction, risk-of-bias (JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies), and certainty of the evidence (GRADE® system) assessment were conducted independently by two reviewers. Meta-analyses were performed using a random-effects model, with standardized mean differences and 95% confidence intervals. ABR wave I amplitudes were analyzed for click (80 and 90 dB SPL) and tone-burst stimuli stratified by frequency. RESULTS: Among 3,008 identified records, 12 studies were included in the review and five in the meta-analysis. All included studies used ABR measures to investigate CS, with wave I amplitude being the most frequently evaluated biomarker. Meta-analysis demonstrated a significant reduction in ABR wave I amplitude in aged rodents compared with young controls for both click- and tone-burst-evoked responses. Tone-burst ABR showed no significant differences among the evaluated frequencies. These findings should be interpreted with caution due to the limited number of studies and the methodological heterogeneity, which may have reduced statistical power and comparability. CONCLUSIONS: The evidence supports ABR wave I amplitude as a sensitive electrophysiological marker of age-related CS in rodents. Nevertheless, further studies with standardized protocols are needed to strengthen its diagnostic utility and improve comparability across studies.

Animals↗

The effectiveness of digital health interventions for type 2 diabetes in underserved populations: A systematic review and meta-analysis.

This systematic review and meta-analysis of 12 randomized controlled trials (1835 participants) evaluated whether digital health interventions (DHIs) improve glycemic control among underserved adults with type 2 diabetes (T2D), including racial/ethnic minority, low-income, Medicaid-insured, rural, and low-health-literacy populations. Searches of PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to December 20, 2025 identified eligible parallel-group randomized controlled trials reporting change in hemoglobin A1c (HbA1c). Two reviewers independently screened studies, extracted data, and assessed risk of bias using the revised Cochrane Risk of Bias 2 tool. Random-effects meta-analysis showed that DHIs produced a modest but statistically significant HbA1c reduction versus control (mean difference, -0.37 %age points; 95% CI, -0.44 to -0.30; P&#x202f;<&#x202f;.0001; equivalent to -4.0&#x202f;mmol/mol). Heterogeneity was moderate-to-substantial (I&#xb2; = 69.9%). Subgroup analyses suggested directionally similar effects by population group and intervention modality, but interpretation was limited by study-level data and the small number of trials. Funnel-plot inspection and Egger's test (P&#x202f;=&#x202f;.31) did not suggest major small-study effects, although power was limited. Overall certainty for HbA1c was moderate. DHIs may support more equitable diabetes care when implemented with cultural tailoring, language access, digital-literacy support, and technology-access safeguards.

Humans↗

Meta-analysis. A quantitative approach to research integration.

Meta-analysis is being used with increasing frequency in clinical medicine as an attempt to improve on traditional methods of narrative review by systematically aggregating information and quantifying its impact. Combining data from several studies using meta-analysis can increase statistical power, provide insight into the nature of relationships among variables, and increase generalizability of results more rigorously than less quantitative review methods. Like all review methods, meta-analysis can be limited by sampling bias, inadequate data, and biased outcome interpretation. Still, the advantages noted above make meta-analysis a methodology that warrants testing and empirical evaluation.

Data Collection↗

Assessing linkage of immunoglobulin E using a meta-analysis approach.

We report results using a new meta-analysis procedure to assess linkage of immunoglobulin E (IgE), an asthma related quantitative trait, using the nine data sets provided by the Genetic Analysis Workshop 12. This meta-analysis procedure combines univariate Haseman-Elston statistics across studies gaining strength by collating possibly distinct marker maps. We performed univariate Haseman-Elston over all data sets and identified linkage (p < 0.05) to some marker in at least one study on virtually every chromosome. Using the proposed meta-analysis procedure, we detected suggestive linkage (p-value < 7.4 x 10(-4), [Lander and Kruglyak, Nat Genet 11:214-47, 1995]) for two regions on chromosome 4 (around 50 and 150 cM) and one region on chromosome 11 (around 125 cM). We also identified areas which were evocative (p-value < 0.02) for linkage: chr 5-40 cM, chr 7-98 cM, chr 9-65 cM, chr 13-110 cM, chr 16-10 cM and approximately 105 cM, chr 17-70 cM, and chr 20-25 cM.

Adult↗

A likelihood approach to meta-analysis with random effects.

In a meta-analysis of a set of clinical trials, a crucial but problematic component is providing an estimate and confidence interval for the overall treatment effect theta. Since in the presence of heterogeneity a fixed effect approach yields an artificially narrow confidence interval for theta, the random effects method of DerSimonian and Laird, which incorporates a moment estimator of the between-trial components of variance sigma B2, has been advocated. With the additional distributional assumptions of normality, a confidence interval for theta may be obtained. However, this method does not provide a confidence interval for sigma B2, nor a confidence interval for theta which takes account of the fact that sigma B2 has to be estimated from the data. We show how a likelihood based method can be used to overcome these problems, and use profile likelihoods to construct likelihood based confidence intervals. This approach yields an appropriately widened confidence interval compared with the standard random effects method. Examples of application to a published meta-analysis and a multicentre clinical trial are discussed. It is concluded that likelihood based methods are preferred to the standard method in undertaking random effects meta-analysis when the value of sigma B2 has an important effect on the overall estimated treatment effect.

Antihypertensive Agents↗

[Meta-analysis of clinical trials for chemotherapy in cancer].

Meta-analysis has attracted great interest among clinical practitioners in recent years, leading to a steady output of related publications. Meta-analytic articles are easily found in the MEDLINE database using the publication-type option. This paper reviews how to use and understand meta-analysis with a special reference to chemotherapy applied to cancer patients. It is described in relationship to evidence-based medicine (EBM) and clinical practice guidelines. Cochrane collaboration is also referred to as an active voluntary organization conducting meta-analysis. In the technical sections, statistical issues and graphic representations are clearly illustrated using the example of hepatic arterial infusion for colorectal cancer patients. The difference between fixed and random effects models is briefly explained. Finally, an example from Cochrane Library, namely progestagen therapy for endometrial cancer, is illustrated to show the implications of meta-analysis for clinical practice.

Clinical Trials as Topic↗

Vitamin A supplementation and child mortality. A meta-analysis.

OBJECTIVE: A two-part meta-analysis of studies examining the relationship of vitamin A supplementation and child mortality. DATA SOURCES: We identified studies by searching the MEDLARS database from 1966 through 1992 and by scanning Current Contents and bibliographies of pertinent articles. STUDY SELECTION: All 12 vitamin A controlled trials with data on mortality identified in the search were used in the analysis. DATA EXTRACTION: Data were independently extracted by two investigators who also assessed the quality of each study using a previously described method. DATA SYNTHESIS: We formally tested for heterogeneity across studies. We pooled studies using the Mantel-Haenszel and the DerSimonian and Laird methods and adjusted for the effect of cluster assignment of treatment groups in community-based studies. Vitamin A supplementation to hospitalized measles patients was highly protective against mortality (DerSimonian and Laird odds ratio, 0.39; 95% confidence interval, 0.22 to 0.66; P = .0004) (part 1 of the meta-analysis). Supplementation was also protective against overall mortality in community-based studies (DerSimonian and Laird odds ratio, 0.70; clustering-adjusted 95% confidence interval, 0.56 to 0.87; P = .001) (part 2 of the meta-analysis). CONCLUSIONS: Vitamin A supplements are associated with a significant reduction in mortality when given periodically to children at the community level. Factors that affect the bioavailability of large doses of Vitamin A need to be studied further. Vitamin A supplements should be given to all measles patients in developing countries whether or not they have symptoms of vitamin A deficiency.

Child↗

Post-Lyme borreliosis syndrome: a meta-analysis of reported symptoms.

BACKGROUND: This meta-analysis compares the prevalence of fatigue, musculoskeletal pain, and neurocognitive difficulties in patients who have had Lyme borreliosis (LB) and control subjects without LB. METHODS: Titles and abstracts in PubMed were reviewed for studies with data on the symptoms listed above that compared patients who had had LB with controls from the general population. Five studies with 504 patients and 530 controls were included in the meta-analysis. RESULTS: The prevalence of symptoms was significantly higher in the LB patients, with P-values between <0.00001 and 0.007 for 8 of the 10 symptoms in the three categories listed above. The higher prevalence of certain neurocognitive symptoms but not others, in the same pattern as reported in the literature, is further confirmation of this syndrome. The pattern of symptoms appears to be different from that seen in fibromyalgia, depression, and chronic fatigue syndrome. CONCLUSIONS: This meta-analysis provides strong evidence that some patients with LB have fatigue, musculoskeletal pain, and neurocognitive difficulties that may last for years despite antibiotic treatment.

Adult↗

Meta-DiSc: a software for meta-analysis of test accuracy data.

BACKGROUND: Systematic reviews and meta-analyses of test accuracy studies are increasingly being recognised as central in guiding clinical practice. However, there is currently no dedicated and comprehensive software for meta-analysis of diagnostic data. In this article, we present Meta-DiSc, a Windows-based, user-friendly, freely available (for academic use) software that we have developed, piloted, and validated to perform diagnostic meta-analysis. RESULTS: Meta-DiSc a) allows exploration of heterogeneity, with a variety of statistics including chi-square, I-squared and Spearman correlation tests, b) implements meta-regression techniques to explore the relationships between study characteristics and accuracy estimates, c) performs statistical pooling of sensitivities, specificities, likelihood ratios and diagnostic odds ratios using fixed and random effects models, both overall and in subgroups and d) produces high quality figures, including forest plots and summary receiver operating characteristic curves that can be exported for use in manuscripts for publication. All computational algorithms have been validated through comparison with different statistical tools and published meta-analyses. Meta-DiSc has a Graphical User Interface with roll-down menus, dialog boxes, and online help facilities. CONCLUSION: Meta-DiSc is a comprehensive and dedicated test accuracy meta-analysis software. It has already been used and cited in several meta-analyses published in high-ranking journals. The software is publicly available at http://www.hrc.es/investigacion/metadisc_en.htm.

Clinical Laboratory Techniques↗

The efficacy of low-power lasers in tissue repair and pain control: a meta-analysis study.

OBJECTIVE: We used statistical meta-analysis to determine the overall treatment effects of laser phototherapy on tissue repair and pain relief. BACKGROUND DATA: Low-power laser devices were first used as a form of therapy more than 30 years ago. However, their efficacy in reducing pain or promoting tissue repair remains questionable. METHODS: Following a literature search, studies meeting our inclusion criteria were identified and coded. Then, the effect size of laser treatment, that is, Cohen's d, was calculated from each study using standard meta-analysis procedures. RESULTS: Thirty-four peer-reviewed papers on tissue repair met our inclusion criteria and were used to calculate 46 treatment effect sizes. Nine peer-reviewed papers on pain control met the inclusion criteria and were used to calculate nine effect sizes. Meta-analysis revealed a positive effect of laser phototherapy on tissue repair (d = +1.81; n = 46) and pain control (d = +1.11; n = 9). The positive effect of treatment on specific indices of tissue repair was evident in the treatment effect sizes determined as follows: collagen formation (d = +2.78), rate of healing (d = +1.57), tensile strength (d = +2.13), time needed for wound closure (d = +0.76), tensile stress (d = +2.65), number and rate of degranulation of mast cells (d = +1.87), and flap survival (d = +1.95). Further, analysis revealed the positive effects of various wavelengths of laser light on tissue repair, with 632.8 nm having the highest treatment effect (d = +2.44) and 780 nm the least (d = 0.60). The overall treatment effect for pain control was positive as well (d = +1.11). The fail-safe number-that is, the number of studies in which laser phototherapy has negative or no effect-needed to nullify the overall outcome of this analysis was 370 for tissue repair and 41 for pain control. CONCLUSIONS: These findings mandate the conclusion that laser phototherapy is a highly effective therapeutic armamentarium for tissue repair and pain relief.

Female↗

Critical reading of the meta-analysis of clinical trials.

In this paper we shall present the general principles of meta-analysis and will then discuss the various factors needed to evaluate a meta-analysis: description of the problem; definition of the outcome(s) (primary and secondary); methods for identifying and selecting trials for inclusion; statistical methods used; and the presentation and discussion of the results. We shall then examine other problems such as the detection of bias, the validity of the information provided by the meta-analysis, the problem of heterogeneity, the sensitivity and robustness of the meta-analysis, quality criteria for a meta-analysis, and how to locate published meta-analyses. Finally we present a decision algorithm which should help answer the question: should and can the results from the meta-analysis be integrated into clinical practice?

Bias↗

Association Between Statin Use and Dry Eye Disease: A Systematic Review and Meta-Analysis.

TOPIC: This systematic review and meta-analysis evaluated the literature-pooled association between statins and dry eye disease (DED). CLINICAL RELEVANCE: Statins, a common treatment modality for dyslipidemia, have been proposed as a potential contributor to DED via their activity in meibomian gland epithelial cells. However, single studies show mixed evidence, and there remains an unmet clinical need to clarify whether statin exposure is associated with DED. METHODS: This review was reported in accordance with the Preferred Reporting Items for Systematic Reviews of Interventions (PRISMA) 2020 statement and was registered a priori on PROSPERO (CRD420251238004). Ovid MEDLINE, Embase, CINAHL, Web of Science, CENTRAL, and the reference lists of relevant reviews were searched from inception to November 2025 for studies reporting the association between statin use and DED. Random-effects meta-analysis using inverse-variance weighting was conducted to pool effect estimates as odds ratios with 95% confidence intervals (CIs). Study risk of bias was appraised using the ROBINS-E tool, and the certainty of the evidence was reported using the GRADE framework. RESULTS: Six observational studies were included in the meta-analysis (n = 560,821; 356,012/559,141 [63.7%] statin users). The pooled analysis revealed a significant positive association between statins and DED (odds ratio 1.09, 95% CI 1.05-1.13, P < .001), with an absolute risk difference of 10.2 more DED cases per 1000 (95% CI 5.5 more to 15.2 more). This result was derived from very low-certainty evidence given limitations in study design and serious inconsistency. Subgroup and sensitivity analyses for risk of bias (P = .123), method of outcome ascertainment (P = .737), type of effect estimate (P = .496), and leave-one-out analyses showed no evidence of effect modification and demonstrated consistent direction of association across studies. CONCLUSION: Statin use was associated with a small but statistically significant increase in DED, limited by very low-certainty evidence. Physicians should monitor for and educate patients on ocular surface symptoms in patients using statins with pre-existing DED risk factors. Future studies should use standardized DED diagnostic criteria to investigate the impact of statin dose, type, and duration to better characterize this potential association.

Humans↗

Adjuvant chemotherapy in gastric cancer: a meta-analysis of randomized trials and a comparison with previous meta-analyses.

AIMS AND BACKGROUND: Up to now adjuvant chemotherapy after curative resection for gastric cancer (GC) has been considered an experimental approach. The results of existing phase III randomized trials comparing chemotherapy with control after surgery are controversial. Three meta-analyses have been published in recent years. It is likely that each of them presents a theoretical bias, mainly as regards the inclusion criteria of the trials. In this article we re-examine this potential bias, highlighting the differences between the present and past meta-analyses on adjuvant chemotherapy for GC. METHODS: Only randomized controlled clinical trials comparing systemic adjuvant chemotherapy with control after radical resection of GC were eligible. Total mortality was assessed as outcome measure of the treatment effect and a pooled odds ratio was calculated using the Peto-Mantel-Haenszel method. RESULTS: After the selection process 17 papers (18 comparisons) proved eligible for inclusion in the meta-analysis with a total of 3118 patients, of whom 1546 randomized to the treatment arms and 1572 to the control arms; 762 and 871 deaths occurred in the treatment and control arms, respectively. Statistical analysis suggests an absence of significant heterogeneity between the trials and a significant advantage in survival for adjuvant chemotherapy (pooled odds ratio, 0.72, 95% Cl, 0.62-0.84). CONCLUSIONS: Our meta-analysis would seem to indicate that adjuvant chemotherapy results in a significant survival advantage in patients with GC. However, this observation undoubtedly requires confirmation in large randomized controlled trials including cisplatin before adjuvant chemotherapy after curative resection for GC can be proposed for use in clinical practice.

Antineoplastic Combined Chemotherapy Protocols↗

Repeated-measures modeling improved comparison of diagnostic tests in meta-analysis of dependent studies.

OBJECTIVE: Current methods for meta-analysis of diagnostic tests do not allow utilizing all the information from papers in which several tests have been studied on the same patient sample. We demonstrate how to combine several studies of diagnostic tests, where each study reports on more than one test and some tests (but not necessarily all of them) are shared with other papers selected for the meta-analysis. We adopt statistical methodology for repeated measurements for the purpose of meta-analysis of diagnostic tests. STUDY DESIGN AND SETTING: The method allows for missing values of some tests for some papers, takes into account different sample sizes of papers, adjusts for background and confounding factors including test-specific covariates and paper-specific covariates, and accounts for correlations of the repeated measurements within each paper. It does not need individual-level data, although it can be modified to use them, and uses the two-by-two table of test results vs. gold standard. RESULTS: The results are translated from diagnostic odds ratios (DOR) to more clinically useful measures such as predictive values, post-test probabilities, and likelihood ratios. Models to capture between-study variation are introduced. The fit and influence of specific studies on the regression can be evaluated. Furthermore, model-based tests for homogeneity of DORs across papers are presented. CONCLUSION: The use of this new method is illustrated using a recent meta-analysis of the D-dimer test for the diagnosis of deep venous thrombosis.

Biomarkers↗

The application of meta-analysis in assessing racial differences in the effects of antihypertensive medication.

Meta-analysis is an important technique for synthesizing research findings. Although the statistical foundations of meta-analysis continue to be debated, few question its value as a rigorous framework for organizing literature reviews. In recent years, there has been increasing emphasis on the use of meta-analysis not only to summarize the central tendency of findings but also to explain variation between studies. This article reviews the major steps in a meta-analysis with an emphasis on comparative analysis of subgroups of studies. A meta-analysis of the antihypertensive efficacy of calcium channel blockers is used to illustrate how a comparative analysis can be applied to investigate racial variation in the effects of calcium channel blockers. A statistically significant trend is found between the proportion of African-American hypertensive subjects and the mean reduction in blood pressure. Meta-analytic techniques also are applied to explore possible confounders due to differences in research design and patient characteristics.

Age Factors↗

Vision anomalies and reading skill: a meta-analysis of the literature.

We report a meta-analysis of studies of the relation of vision anomalies to reading skill. Meta-analysis is a quantitative technique for combining the results of multiple studies that reduces the subjectivity of literature reviews. The results of the analysis of 34 studies of vision anomalies and reading skill that met the criteria for inclusion in the meta-analysis showed that hyperopia, exophoria at near, vertical phoria, anisometropia, and aniseikonia are associated with below average reading performance. Myopia and esophoria and esophoria at far are associated with average and above average reading performance. Reduced visual acuity, astigmatism, esophoria at near, fusional convergence and divergence, strabismus, nearpoint of convergence, and stereopsis were not found to be associated with reading performance.

Depth Perception↗

The efficacy of problem solving therapy in reducing mental and physical health problems: a meta-analysis.

This paper describes a meta-analysis of 31 studies that examined the efficacy of problem solving therapy (PST). The meta-analysis, encompassing 2895 participants, showed that PST is significantly more effective than no treatment (d=1.37), treatment as usual (d=0.54), and attention placebo (d=0.54), but not significantly more effective than other bona fide treatments offered as part of a study (d=0.22). Significant moderators included whether the PST included problem-orientation training, whether homework was assigned, and whether a developer of PST helped conduct the study.

Adult↗