Work overview

Section 07 of 19

Statistical analysis

Prebiotics, probiotics, and synbiotics therapy in critically ill patients: a systematic review and network meta-analysis

Junji Hatakeyama, Ryo Yamamoto, Minoru Yoshida, Kohei Yamada, Kazushige Inoue, Takayuki Irahara, Satomi Ichimaru, Nobuto Nakanishi, Naoki Higashibeppu, Kensuke Nakamura, and Joji Kotani · 2026

Contents

Section 07 of 19

  1. 01Introduction
  2. 02Methods
  3. 03Search strategy
  4. 04Study selection and inclusion criteria
  5. 05Outcomes
  6. 06Data extraction and risk of bias assessment
  7. 07Statistical analysis
  8. 08Subgroup and sensitivity analyses
  9. 09Results
  10. 10Discussion
  11. 11Conclusion
  12. 12Authors’ contributions
  13. 13Consent for publication
  14. 14Ethics approval and consent to participate
  15. 15Declaration of Generative AI and AI-assisted technologies in the writing process
  16. 16Funding
  17. 17Availability of data and material
  18. 18Data availability
  19. 19Declaration of competing interest
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Work overview

Section 7 of 19

Statistical analysis

Junji Hatakeyama, Ryo Yamamoto, Minoru Yoshida, Kohei Yamada, Kazushige Inoue, Takayuki Irahara, Satomi Ichimaru, Nobuto Nakanishi, Naoki Higashibeppu, Kensuke Nakamura, and Joji Kotani · about 1 minutes

Binary outcomes were summarized as risk ratios (RRs) with 95% confidence intervals (CIs), whereas continuous outcomes were summarized as mean differences (MDs) with 95% CIs. For continuous outcomes, the mean, standard deviation (SD), and number of participants analyzed per group were extracted. When medians with ranges or interquartile ranges were reported, these summary statistics were converted to means and SDs using validated methods to enable inclusion in the meta-analyses [17,18].

A frequentist network meta-analysis was conducted using a random-effects model as the primary analytical approach. Placebo and usual care were combined into a single control node. Global inconsistency was evaluated using the design-by-treatment interaction model, whereas local inconsistency was assessed using the node-splitting approach. The probability of each intervention ranking as the most effective for each outcome was estimated, and treatment rankings were summarized using the surface under the cumulative ranking curve (SUCRA). Conventional pairwise meta-analyses were also performed for all available direct comparisons to summarize direct evidence and support the assessment of consistency between direct and indirect estimates. For outcomes with a sufficient number of studies, comparison-adjusted funnel plots were constructed to explore potential small-study effects. Funnel plot asymmetry was additionally evaluated using Egger’s regression test applied to the comparison-adjusted effect sizes. All analyses were performed using Stata/SE (version 17.0; StataCorp, College Station, TX, USA) with the network meta-analysis command suite [19]. Statistical significance was set at p < 0.05.