Advertisement
Mayo Clinic Proceedings Home

Regarding Empiricism and Rationalism in Medicine and 2 Medical Worldviews

      To the Editor:
      I am pleased that our work on medical reversal
      • Prasad V.
      • Vandross A.
      • Toomey C.
      • et al.
      A decade of reversal: an analysis of 146 contradicted medical practices.
      and my recent commentary
      • Prasad V.
      Why randomized controlled trials are needed to accept new practices: 2 medical worldviews.
      describing 2 schools of clinical reasoning have drawn attention and generated discussion from many, including leaders in academic medicine.
      • Lanier W.L.
      • Rajkumar S.V.
      Empiricism and rationalism in medicine: can 2 competing philosophies coexist to improve the quality of medical care [editorial]?.
      In response, I wanted to make 2 points. First, when it comes to untested practices with strong preclinical rationale and improved surrogate end points, I only oppose their widespread use when there are no ongoing studies examining patient-centered end points. If such practices are currently being tested in randomized controlled trials (RCTs) powered for hard outcomes, then the use of the practice on a provisional basis in the general population is appropriate based on a shared decision-making process between physicians and patients, fully acknowledging the limited evidence base. This is the philosophical footing for the US Food and Drug Administration's accelerated approval program.
      The one major caveat I would add is that community use is warranted as long as that use does not hinder the ongoing enrollment of clinical trials meant to assess that practice. One example is intracavitary catheter-based breast brachytherapy. The first such device was approved through the US Food and Drug Administration's 510(k) mechanism in 2002, with very limited safety (and even more limited efficacy) data. In the years since, the device's use has skyrocketed, and RCTs testing the device's impact on hard outcomes has been hindered by most patients being treated off protocol. One editorialist noted that if only a fraction of the patients who received breast brachytherapy in the community “had been treated on the trial instead of off protocol, the study would have closed…and we would already have the results.”
      • Malin J.L.
      When hope hinders science and patient-centered care [editorial].
      As long as new practices are being tested in RCTs that have met recruitment goals, provisional approval based on surrogates is not unreasonable.
      The second point concerns the argument
      • Lanier W.L.
      • Rajkumar S.V.
      Empiricism and rationalism in medicine: can 2 competing philosophies coexist to improve the quality of medical care [editorial]?.
      • Halperin E.C.
      The proton problem.
      that some medical practices are like parachutes: their benefit is so clear, randomized trials are unnecessary. In general, I agree that there are such cases in medicine, but while proponents are quick to think that their particular practice is a parachute, the truth is that very few are.
      • Prasad V.
      • Cifu A.
      A medical burden of proof: towards a new ethic.
      Empirical evidence supports this claim. Pereira et al
      • Pereira T.V.
      • Horwitz R.I.
      • Ioannidis J.P.
      Empirical evaluation of very large treatment effects of medical interventions.
      examined 85,002 forest plots from more than 3000 Cochrane reviews and specifically focused on practices with very large treatment effects (those with nominally significant results and a magnitude of benefit with an odds ratio ≥5). These interventions with very large effects were less likely to examine mortality and more likely to have small sample sizes than other studies, and 98% of these effects became smaller in subsequent studies or meta-analysis. Only one intervention (extracorporeal oxygenation for severe respiratory failure in newborns) had a large effect on mortality in the entire Cochrane Database of Systematic Reviews.
      There will always be a place for the thoughtful deliberation of physicians in medicine; however, I continue to believe that given the pressures of the modern marketplace and university promotions, most decisions should be firmly grounded in RCTs powered for hard end points.
      The views and opinions of Dr Prasad do not necessarily reflect those of the National Institutes of Health or the National Cancer Institute.

      References

        • Prasad V.
        • Vandross A.
        • Toomey C.
        • et al.
        A decade of reversal: an analysis of 146 contradicted medical practices.
        Mayo Clin Proc. 2013; 88: 790-798
        • Prasad V.
        Why randomized controlled trials are needed to accept new practices: 2 medical worldviews.
        Mayo Clin Proc. 2013; 88: 1046-1050
        • Lanier W.L.
        • Rajkumar S.V.
        Empiricism and rationalism in medicine: can 2 competing philosophies coexist to improve the quality of medical care [editorial]?.
        Mayo Clin Proc. 2013; 88: 1042-1045
        • Malin J.L.
        When hope hinders science and patient-centered care [editorial].
        J Clin Oncol. 2012; 30: 4283-4284
        • Halperin E.C.
        The proton problem.
        Lancet Oncol. 2013; 14: 1046-1048
        • Prasad V.
        • Cifu A.
        A medical burden of proof: towards a new ethic.
        Biosocieties. 2012; 7: 72-77
        • Pereira T.V.
        • Horwitz R.I.
        • Ioannidis J.P.
        Empirical evaluation of very large treatment effects of medical interventions.
        JAMA. 2012; 308: 1676-1684

      Linked Article