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Biology, Learning, Psychology, Uncategorized

Hypertension and stopping research studies early

These two topics aren’t related except that while reading an opinion article published on The JAMA Network about the challenges and opportunities of implementing the most recent guidelines for the diagnosis and treatment of hypertension I learned that some clinical studies are stopped early because the study is showing positive results.

Hypertension first. The American College of Cardiology/American Heart Association released new guidelines that lowers the threshold for high blood pressure (greater than 130/80 mmHg from greater than 140/90 mmHg). This means that in the US there are now 46% of people who are classified as having hypertension. I honestly did not realize that so many people have hypertension, although I did know that it is extensive. You can read the full piece here, but I just want to look at one angle of it. Ioannidis (2017) states that the greatest benefit of the recommendations “may be that they emphasize, most likely for young adults, lifestyle interventions… In principle, shifting the health care system more toward prevention with lifestyle measures”. I agree completely and have often been very frustrated by the reactionary nature of our health care system. This is one of the reasons that I enjoy teaching human biology: I believe that if you actually understand how your body works a little better it becomes easier to make healthier choices. However, Ioannidis also points out that “it is unclear whether patients and clinicians are ready for such a change and whether these tens of millions of individuals will be able to obtain appropriate counseling and endorse effective, sustainable lifestyle modifications.” That’s the thing isn’t it. If you don’t have support, and you have no place or no one to learn from how can you make the changes that you need. A doctor’s visit of 15 minutes if you’re lucky isn’t going to teach you what you need to actually be successful at the gym or even with your diet. If you don’t know what natural foods contain potassium (bananas are one source) than how can you increase it. And while the Internet might hold the answers you need, you need a base line of knowledge to be able to assess the validity of any claims, lest you get caught up in the ridiculous claims made on sites that I refuse to mention here because I don’t want to send them traffic. So, while I think earlier intervention is positive I share Ioannidis’ concern that without support individuals will not be successful through lifestyle interventions and them and their doctors will resort to medications which can be expensive and do have other risks such as acute kidney failure.

Now onto stopping research trials early because of positive results. On the one hand, I understand this inclination. If a particular treatment is showing significantly better results that placebo (fake treatments that can’t be told apart from the real thing) or the current treatments how can you not stop the trial early to potentially allow those control patients who aren’t receiving the new treatment to get that new treatment sooner. This could literally be the difference between life and death for some individuals. However, particularly when the study includes less than 200 events or between 200 to 500 events, these shortened trials overestimate the benefits of the treatment (up to 70%). Again, if we think about practice, a physician might prescribe a new treatment because it has been shown in a shortened study to have massively better results. However, the individual patients might not experience such an improvement. Now the physician and the patient are trying to figure out what is wrong, why isn’t the patient experiencing the same benefits. Do they continue the treatment? Do they add something else into the mix? Do they discontinue the treatment completely?

Also, what if the long-term risks are missed or underestimated because the study is stopped early. Or what if there was going to be a difference in populations that wasn’t detected because the study was stopped early?

I get it, I get trying to move a treatment into practice but if there is such evidence that these shortened studies “yield treatment effects that are often not credible” (Guyatt, Briel, Glasziou, Bassier, & Montori, 2012) I question the rationality of stopping the studies before they are done.

About Tai Munro

I am passionate about making science, sustainability, and sport accessible through engaging information and activities.

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