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Questioning the methodologic superiority of 'placebo' over 'active' controlled trials
1University of Oxford, Centre for Evidence-Based Medicine, Old Road Campus, Oxford, United Kingdom. jeremy.howick@dphpc.ox.ac.uk
The American Journal of Bioethics : AJOB
|December 10, 2009
Summary
Placebo-controlled trials (PCTs) may be unethical when effective treatments exist. This analysis argues that active-controlled trials (ACTs) are not methodologically inferior, resolving ethical conflicts in clinical research.
Area of Science:
- Clinical Research Ethics
- Methodology
Background:
- Ethical dilemmas arise when placebo-controlled trials (PCTs) withhold effective treatments from participants.
- Clinicians' duty to provide best care suggests using active-controlled trials (ACTs) when established treatments are available.
- Methodological concerns regarding ACTs often favor PCTs.
Purpose of the Study:
- To analyze and refute the purported methodological inferiority of ACTs compared to PCTs.
- To resolve the ethical tension between providing optimal patient care and employing rigorous research methods.
Main Methods:
- Critical analysis of three key arguments claiming ACTs are inferior to PCTs:
- Examination of 'assay sensitivity' in ACTs.
- Evaluation of absolute effect size measurement in ACTs.
- Assessment of participant number requirements for ACTs.
Main Results:
- The three primary arguments for ACTs' methodological inferiority are found to be unacceptable.
- ACTs are not inherently inferior to PCTs in terms of assay sensitivity, effect size measurement, or participant numbers.
- The methodological objections to ACTs do not hold up under scrutiny.
Conclusions:
- The ethical imperative to avoid placebo-controlled trials (PCTs) when effective treatments exist is supported by methodological considerations.
- The perceived methodological disadvantages of active-controlled trials (ACTs) are not valid.
- The ethical conflict between clinical and research ethics regarding trial design is resolved in favor of avoiding PCTs.
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