Institute:Office of National Coordinator (ONC) Workforce Training Curriculum
Component:The Culture of Health Care
Lecture:Phrasing the clinical question
Slide content:Why Are RCTs the Best Evidence for Interventions? Reduction in bias Vitamin C to prevent the common cold (Douglas, Chalker , & Treacy , 2000; Hemila , 2013) Womens Health Initiative (Writing Group for the Women's Health Initiative Investigators, 2002; Chlebowski et al., 2015) Emphasis on clinical end-points and patient-oriented outcomes Cardiac Arrhythmia Suppression Trial (Epstein et al., 1993) New treatments are not necessarily better In radiation oncology, trials of new treatments are as likely as not to be successful ( Soares et al., 2005) 5
Slide notes:5 RCTs provide the best evidence for interventions because they allow us to reduce bias when participants dont know what treatment they are getting. For example, most of you probably know someone who touts the benefits of vitamin C in preventing the common cold. Maybe even you do. We all know people who say that since they started taking vitamin C, they never get colds. However, the reality is that there have been more than thirty RCTs that have assessed this intervention. When you eliminate the bias to people knowing whether they are taking either vitamin C or a placebo, there is no difference in the number of colds that people get. Another example is the Womens Health Initiative. Prior to this study by Chlebowski and colleagues, there was strong belief that postmenopausal estrogen replacement therapy was beneficial for womenthat it reduced heart disease and cognitive deficits. However, this belief was overturned by this very well designed RCT. Another benefit for RCTs is that they tend to focus on clinical endpoints and patient-oriented outcomes, or at least they should. In the 1980s, it was common to prescribe lidocaine [ lie -duh-keyn] whenever a patient had a myocardial infarction in the belief that suppressing cardiac rhythm abnormalities would prevent complications such as fatal ventricular fibrillation [fahy-bruh- ley -shuhn]. However, the Cardiac Arrhythmia [uh- rith -mee-uh] Suppression Trial, which randomized people to lidocaine and no lidocaine, showed that not only was there no benefit for lidocaine, but it was actually dangerous, bringing a quick end to that practice. Theres a common view that any new intervention is better than the old. One researcher looked at radiation oncology trials and noticed that new treatments were just as likely as not to be successful. Just because something new is introduced doesnt mean we cant test it out. However, testing needs to be done in an RCT to demonstrate whether the new approach really is better.