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Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia

Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia

Published on: February 17, 2023

Cluster-randomized controlled trials evaluating complex interventions in general practices are mostly ineffective: a

Andrea Siebenhofer¹, Michael A Paulitsch², Gudrun Pregartner³

¹Institute of General Practice, Goethe University Frankfurt am Main, Theodor-Stern-Kai 7, Frankfurt am Main 60590, Germany; Institute of General Practice and Evidence-based Health Services Research, Medical University of Graz, Auenbruggerplatz 2/9/IV, Graz 8036, Austria.

Journal of Clinical Epidemiology

|November 8, 2017

Summary

Most complex interventions in general practice trials do not outperform routine care. Studies often overestimate treatment effects, emphasizing the need for careful planning in clinical research.

Keywords:

Cluster-randomized controlled trial Complex intervention Effectiveness General practice Shortcomings Systematic review

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Last Updated: Feb 19, 2026

Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia

Meta-Analysis of the Effectiveness and Safety of Shugan Jieyu Capsules for the Treatment of Insomnia

Published on: February 17, 2023

Area of Science:

Clinical Trials
General Practice Research
Health Services Research

Background:

Complex interventions aim to improve healthcare, but their effectiveness in general practice settings requires rigorous evaluation.
Cluster-randomized controlled trials (c-RCTs) are a key methodology for assessing interventions in primary care.

Purpose of the Study:

To determine the frequency with which complex interventions demonstrate superiority over routine care in general practice c-RCTs.
To investigate if discrepancies in study design or statistical assumptions explain observed outcomes.

Main Methods:

Systematic search of major databases (CENTRAL, MEDLINE, EMBASE) for relevant c-RCTs.
Inclusion criteria: general practice setting, patient-relevant primary outcome, minimum 1-year follow-up.
Extraction of effect sizes, P-values, intracluster correlation coefficients (ICCs), and quality metrics.

Main Results:

Only 4% of primary outcomes across 29 trials achieved statistical significance after adjustment.
Most studies (86%) failed to show a beneficial effect of complex interventions over routine care.
Intracluster correlation coefficients and anticipated effect sizes were often overestimated in study planning.

Conclusions:

The majority of complex interventions evaluated in general practice c-RCTs do not prove superior to routine care.
Overly optimistic assumptions regarding treatment effects and sample size calculations are common.
Prospective planning and realistic effect size estimation are crucial for designing effective clinical studies in primary care.