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Evidence-based recommendations for blinding in surgical trials.

Pascal Probst^1,2, Steffen Zaschke^3,4, Patrick Heger^3,4

¹Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany. pascal.probst@med.uni-heidelberg.de.

Langenbeck'S Archives of Surgery

|March 3, 2019

Summary

Blinding in surgical randomized controlled trials (RCT) is often not fully utilized. Improving blinding, especially for surgeons, can lead to more reliable trial outcomes and reduce bias.

Keywords:

Bias Blinding Cochrane risk of bias assessment tool Detection bias Performance bias Randomized controlled trial Risk of bias Surgery Systematic review

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Area of Science:

Medical Research Methodology
Surgical Clinical Trials
Evidence-Based Medicine

Background:

Blinding is crucial in randomized controlled trials (RCT) to minimize performance and detection bias.
Lack of blinding in pharmacological trials is linked to overestimation of treatment effects.
Surgical interventions present unique challenges to blinding due to their physical nature.

Purpose of the Study:

To analyze the status and potential of blinding in general and abdominal surgery RCT.
To investigate the influence of blinding on outcomes in surgical trials.
To provide evidence-based recommendations for future surgical trial blinding.

Main Methods:

Systematic literature search of CENTRAL, MEDLINE, and Web of Science for surgical RCT published since 1996.
Extraction of study characteristics and blinding methods.
Analysis of blinding status for patients, surgeons, data collectors, outcome assessors, and data analysts.
Investigation of the association between blinding and trial outcomes.

Main Results:

378 RCT involving 62,522 patients were analyzed; only 24.0% of patients were blinded.
Significant potential for increased blinding existed, ranging from 69% for outcome assessors to 98% for data analysts.
Failure to blind surgeons when possible was associated with significantly more pronounced trial outcomes (OR 13.670, p=0.0289).

Conclusions:

The potential for blinding in surgical RCT remains largely unexploited.
Effective blinding is an important quality measure for surgical research.
Recommendations are provided to enhance blinding practices in future surgical trials.