Interpretation of subgroup analyses in systematic reviews: A tutorial

Richardson, Marty; Garner, Paul; Donegan, Sarah

doi:10.1016/j.cegh.2018.05.005

Cited by 382 publications

(224 citation statements)

References 5 publications

Supporting

Mentioning

222

Contrasting

Unclassified

Order By: Relevance

“…The results of the subgroup analysis are shown in Table . In the subgroup analysis, a covariate was considered a source of heterogeneity when the two split subsets had no statistical heterogeneity, as indicated by a P ‐value greater than 0.05, and when both the I 2 values of the two split subsets moderately to significantly decreased compared to that of the general analysis . While overall heterogeneity existed ( P = 0.013, I 2 = 72%), we found that lesion size ( P = 0.076, I 2 = 47%, for subgroup <50 mm, P = 0.498, I 2 = 0, for subgroup ≥50 mm), number of included lesions in the studies ( P = 0.09, I 2 = 41%, for subgroup <90, P = 0.092, I 2 = 41%, for subgroup ≥90), and blinding to the reference standard when performing the index test ( P = 0.062, I 2 = 52%, for subgroup yes, P = 0.221, I 2 = 0, for subgroup unclear) may be the sources of heterogeneity for the ADC value in discriminating poorly differentiated HCCs.…”

Section: Resultsmentioning

confidence: 76%

Diagnostic accuracy of quantitative diffusion parameters in the pathological grading of hepatocellular carcinoma: A meta‐analysis

She

Wang

Yang

et al. 2019

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Background: Accurate preoperative assessment of the pathological grade of hepatocellular carcinoma (HCC) could greatly benefit prognostic predictions. Purpose: To assess and compare the diagnostic accuracy of the apparent diffusion coefficient (ADC) and tissue diffusivity (D) for the noninvasive pathological grading of HCC. Study Type: Meta-analysis. Data Sources: PubMed/Medline, EMBASE, the Web of Science, and the Cochrane Library were searched to find related original articles published up to May 30, 2019. Field Strength/Sequence: Diffusion-weighted imaging (DWI) and/or intravoxel incoherent motion (IVIM) were performed with a 1.5T or 3.0T scanner. Assessment: The Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to assess the methodologic quality. Statistical Tests: The bivariate random-effects model was used to obtain the pooled sensitivity and specificity, and the area under summary receiver operating characteristic curve (AUROC) was obtained. Subgroup analyses were performed. Results: A total of 16 original articles (1428 HCCs) were included. Most studies had a low to unclear risk of bias and minimal concerns regarding applicability. For the discrimination of well-differentiated HCCs, the pooled sensitivity and specificity of the ADC value were 85% and 92%, respectively. For the discrimination of poorly differentiated HCCs, the pooled sensitivity and specificity of the ADC value and D were 84% and 80%, and 92% and 77%, respectively. The summary AUROC of D (0.94) was significantly higher than that of ADC (0.89) (z = -2.718, P = 0.007). The subgroup analyses identified three covariates including size, number of included lesions in the studies, and blindness to the reference standard as possible sources of heterogeneity. Data Conclusion: This meta-analysis showed that the ADC and D values had a high to excellent accuracy for the noninvasive pathological grading of HCCs and that the D value was superior to the ADC value for discriminating poorly differentiated HCCs. Level of Evidence: 3 Technical Efficacy Stage: 2 J. MAGN. RESON. IMAGING 2020;51:1581-1593 H EPATOCELLULAR CARCINOMA (HCC) is the most common type of primary malignant liver neoplasm and the second cause of malignancy-related death worldwide. 1Although treatments have progressed in recent years, the prognosis of HCC patients remains poor because of the high recurrence rate. 2 Studies have confirmed that the pathological View this article online at wileyonlinelibrary.com.

show abstract

Section: Resultsmentioning

confidence: 76%

Diagnostic accuracy of quantitative diffusion parameters in the pathological grading of hepatocellular carcinoma: A meta‐analysis

She

Wang

Yang

et al. 2019

Magnetic Resonance Imaging

View full text Add to dashboard Cite

show abstract

“…A number of subgroup analyses were conducted to investigate whether factors such as dose, geographical location, in/outpatient settings, or aetiology modify the treatment effect. Overall, while some of the analyses revealed a significant subgroup effect ( P < 0.1 indicating a statistically significant subgroup effect), high heterogeneity between findings within each group and/or the small number of trials and participants contributing to each subgroup resulted in uncertainty as to whether these subgroup differences matter. Another limitation is that the definitions of diarrhoea and the inclusion criteria, such as the duration of symptoms prior to the inclusion, differed.…”

Section: Discussionmentioning

confidence: 96%

Systematic review with meta‐analysis: Lactobacillus rhamnosus GG for treating acute gastroenteritis in children – a 2019 update

Szajewska

Kołodziej

Gieruszczak‐Białek

et al. 2019

Aliment Pharmacol Ther

View full text Add to dashboard Cite

Background:Recently, evidence from a large randomised controlled trial (RCT) negated efficacy of Lactobacillus rhamnosus GG for treating acute gastroenteritis in children.Aim: To review RCTs in which L rhamnosus GG was used to treat acute gastroenteritis in children. Methods:The Cochrane Library, MEDLINE, and EMBASE databases were searched from May 2013 (end of last search) to January 2019. The primary outcomes were stool volume and duration of diarrhoea.Results: Eighteen RCTs (n = 4208) were included. Compared with placebo or no treatment, L rhamnosus GG use had no effect on stool volume but was associated with a reduced duration of diarrhoea (15 RCTs, n = 3820, mean difference, MD −0.85 day, 95% CI −1.15 to −0.56). L rhamnosus GG was effective when used at a daily dose of ≥10 10 CFU or <10 10 CFU; however, the latter produced results of borderline significance. L rhamnosus GG was more effective when used in European countries compared with non-European countries, particularly when considered by region.L rhamnosus GG use was associated with a reduced duration of hospitalisation. One RCT found that L rhamnosus GG had no effect on the total clinical severity score at 14 days after enrolment. Conclusions:Despite a recent large RCT demonstrating no effect of L rhamnosus GG, current evidence shows that, overall, L rhamnosus GG reduced both the duration of diarrhoea (with a higher impact in European countries) and hospitalisation in inpatients. These findings should be viewed in the context of the high heterogeneity and methodological limitations of the included trials. | 1377SZAJEWSKA Et Al.

show abstract

“…A number of subgroup analyses were conducted to investigate whether factors such as dose, country's Human Development Index, setting or aetiology modify the treatment effect. Overall, while some of the analyses revealed a significant subgroup effect, high heterogeneity between findings within each group and/or the small number of trials and participants contributing to each subgroup resulted in uncertainty as to whether these subgroup differences matter.…”

Section: Discussionmentioning

confidence: 97%

Systematic review with meta‐analysis: Saccharomyces boulardii for treating acute gastroenteritis in children—a 2020 update

Szajewska

Kołodziej

Zalewski

2020

Aliment Pharmacol Ther

View full text Add to dashboard Cite

Summary Background There is still controversy with regard to the efficacy of individual probiotic strains for the management of acute gastroenteritis. Aim To update evidence on use of Saccharomyces boulardii for treating acute gastroenteritis in children. Methods The Cochrane Library, MEDLINE and EMBASE databases were searched from inception to December 2019 for randomised controlled trials (RCTs) that compared use of S boulardii with no S boulardii (defined as placebo or no treatment). The grey literature was searched through Google search. Authors of the original papers and S boulardii manufacturers were contacted for additional data. Results Twenty‐nine RCTs (among them, 20 newly identified trials) were included. Only 38% of trials adequately generated their randomisation sequence, only 17% adequately concealed allocation and only one trial adequately blinded participants, study personnel and outcome assessors. However, 83% provided complete outcome data. None of the trials evaluated the effect of S boulardii on stool volume. Compared with placebo or no treatment, S boulardii use reduced the duration of diarrhoea (23 RCTs, n = 3450, mean difference −1.06 day, 95% CI −1.32 to −0.79; high heterogeneity [I2 = 90%]) (very low quality of evidence). S boulardii use was also associated with a reduced duration of hospitalisation (8 RCTs, n = 999, mean difference −0.85 day, 95% CI −1.35 to −0.34; I2 = 91%) (very low quality of evidence). S boulardii reduced the risk of diarrhoea on day 2 to day 7 (low quality of evidence). Conclusions In children with acute gastroenteritis, low‐ to very low‐quality evidence suggests that S boulardii confers a benefit for several diarrhoeal outcomes.

show abstract

Interpretation of subgroup analyses in systematic reviews: A tutorial

Cited by 382 publications

References 5 publications

Diagnostic accuracy of quantitative diffusion parameters in the pathological grading of hepatocellular carcinoma: A meta‐analysis

Diagnostic accuracy of quantitative diffusion parameters in the pathological grading of hepatocellular carcinoma: A meta‐analysis

Systematic review with meta‐analysis: Lactobacillus rhamnosus GG for treating acute gastroenteritis in children – a 2019 update

Systematic review with meta‐analysis: Saccharomyces boulardii for treating acute gastroenteritis in children—a 2020 update

Contact Info

Product

Resources

About