LTT: John Worrall
March 31 @ 12:00 pm - 1:30 pm
A Less Myopic View of the Virtues of Blinding and of Tests for Blinding in Clinical Trials
John Worrall, London School of Economics
Abstract: Performing a clinical trial double-blind controls for various biases that might affect the outcome if the trial were unblinded. It would seem, then, that a trial that begins and continues to be unblinded carries, other things being equal, greater evidential weight. But if that’s the epistemic ideal, it is an ideal ‘more often honoured in the breach than the observance’: very few trial reports in medicine record tests for retention of blindness, and in the majority of cases where such tests are reported, they are reported as having been failed. Since instituting and retaining blindness is a question of controlling for bias, you might expect the leaders of Evidence-Based Medicine (EBM) to be in the forefront of those deploring this situation. Instead the “Father of EBM”, David Sackett, described testing for retention of blinding as “playing a mug’s game”. And a recent revision of the EBM-inspired CONSORT guidelines governing the reporting of clinical trials dropped all mention of testing for continued blindness.
This paper attempts to develop a clear view of what could have produced this confusing situation. The analysis results in a realistic and nuanced, but still positive view of the virtues of blinding and, especially, of tests for the retention of blinding throughout a trial. This is “practical philosophy”: if the analysis is correct, then it mandates a re-revision of the CONSORT guidelines – adherence to which is virtually a necessary condition for publication in a high-prestige medical journal.
- March 31
12:00 pm - 1:30 pm
- Event Category:
- Lunchtime Talks
- 1117 Cathedral of Learning
4200 Fifth Ave
Pittsburgh, PA 15260 United States