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Developing guidance for a risk-proportionate approach to blinding statisticians within clinical trials: a mixed
Mais Iflaifel1, Kirsty Sprange1, Jennifer Bell2
1Nottingham Clinical Trials Unit, University of Nottingham, Nottingham, UK.
Trials
|February 1, 2023
Summary
Blinding statisticians in clinical trials did not impact reported significance. Guidance was developed to help UK Clinical Trials Units (CTUs) assess risks and make informed decisions on blinding.
Area of Science:
- Clinical Trials Methodology
- Biostatistics
- Research Integrity
Background:
- Existing guidelines recommend blinding statisticians to treatment allocation until final analysis.
- Practice varies significantly among UK Clinical Trials Units (CTUs) regarding statistician blinding.
- This study aimed to develop risk-proportionate guidance for CTUs on blinding statisticians.
Purpose of the Study:
- To assess the impact of unblinded statisticians on reported statistical significance in clinical trials.
- To understand stakeholder perspectives on blinding trial statisticians.
- To develop evidence-based guidance for UK CTUs on a risk-proportionate approach to statistician blinding.
Main Methods:
- A mixed-methods approach combining quantitative analysis of 179 UK clinical trials (2016-2020) and qualitative focus groups with 37 stakeholders.
- Quantitative analysis assessed the association between unblinded statisticians and statistically significant primary outcomes.
- Qualitative focus groups explored stakeholder views on blinding practices, informing guidance development.
Main Results:
- No evidence found that unblinded statisticians were associated with a higher likelihood of reporting statistically significant findings (OR 1.02, 95% CI 0.49-2.13).
- Stakeholder input and data triangulation led to the development of 40 provisional statements, with 10 reaching agreement.
- Guidance comprising 21 recommendations and a Risk Assessment Tool were created for CTUs.
Conclusions:
- This study provides the first guidance document for understanding and deciding on statistician blinding in clinical trials.
- The decision to blind statisticians should be based on a trial-specific assessment of benefits and risks.
- A risk-proportionate framework and tool are provided to aid CTUs in managing statistician blinding decisions.
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