Evidence-based Medicine, Studies and High Blood Pressure

Key terms for studies:

• Randomized: Who receives a treatment is chosen at random.
  
  
• Placebocontrolled: A dummy pill or sham treatment is used so the participant doesnt know whether they received the real treatment.
  
  
• Doubleblind: Neither the participant nor the researcher knows who received the placebo or the real treatment.
  
  
• Statistical significance: A study is significant when it can be shown statistically that the effect is unlikely to be due to chance.
  
  
• Effect size: Effect size tells you how well the treatment works. For example, if a new drug for high blood pressure only lowers blood pressure by 1 mmHg, the effect is very small and, even if statistically significant, the drug would probably not be recommended.

Problems

1. Study quality
   Unfortunately, it is sometimes still difficult. As mentioned above, the gold standard is a randomized, placebo-controlled doubleblind study. Suppose you want to study a particular surgical technique. You can perform a sham operation and make the patient believe they were operated on even if they weren't. But the surgeon knows whether they actually operated or not. That alone is enough to bias the results.
   
   When studying therapies like psychotherapy or physiotherapy, you have the same problem. The therapist knows whether they are delivering the real therapy or a sham one. And participants are likely to notice that as well.
   
   If you study an app, blinding is not possible at all. That means you can never conclusively prove the evidence for an app. Interest groups exploit this to oppose prescribing apps. The necessary studies become bloated and more expensive without guaranteed approval. Even if approved, the costs of such an app can be disproportionate to the potential benefit.
   
   
2. Individual differences
   Studies are designed for the average person. But there is no such thing as an average person. When the American military tried to define how a cockpit should be designed in the last century, they measured hundreds of people and used those measurements to define the "average" person. The surprising result: not a single participant matched the average exactly. Cockpits were then made adjustable simply because people are different.
   
   Applied to blood pressure:
   Imagine a substance that lowers blood pressure in 5% of participants, but you dont know which ones or why. As long as thats the case, you couldnt run a study that proves the substance works, because the average effect across patients would be too small.
   Practical problems: Your doctor has a selection of well-studied drugs they could prescribe. So in theory controlling blood pressure with medication shouldn't be a problem. In practice its different. Everyone reacts differently. Some drugs simply don't work for some people or they cause side effects no matter how strong the evidence is.
   
   
3. Limited data availability or poor data
   For some medical questions there may not be enough evidence, either because there's a lack of research or because of ethical or practical limitations. A concrete example for high blood pressure is differences in how blood pressure is measured. It matters how, where, and by whom it is measured. There was a large study called SPRINT whose results led to lower hypertension thresholds in the U.S. The problem was that the measurements were done differently than in previous studies. In Europe, therefore, no change in practice was judged necessary.

1. Unique patient cases: If a patient has a unique, complex, or rare condition or set of symptoms, it may be necessary to deviate from general evidence-based guidelines and make individualized medical decisions.
   
   
2. Innovative potential: In some cases, new treatment approaches or technologies may be promising and have the potential to significantly improve patient outcomes even though they are not yet sufficiently supported by evidence.
   However, caution is needed here. New procedures can also carry significant risks and unwanted side effects. Think of the Contergan tragedy between 1957 and 1962 (https://de.wikipedia.org/wiki/Contergan-Skandal).
   
   
3. Traditional or alternative therapies: Another area where clinicians may deviate from evidence-based medicine is traditional or alternative therapies that have a long history but often lack strong scientific proof of effectiveness. Many of these methods, such as certain herbal medicines or specific therapies, have been used for generations and may have a positive impact on health. Even if they don't meet the strict criteria of evidence-based medicine, they can be considered as complementary optionsespecially if the patient prefers them and they don't cause harm. In such cases, open communication between doctors and patients is important so they can jointly develop the best possible treatment plan that takes into account the patient's wishes and preferences as well as the treatment's effectiveness and safety.

Conclusion:

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• Informationen Blutdruck: Grundlagen
• Global organizations focused on blood pressure
• Information on Blood Pressure: Basics
• Blood pressure variability what do blood pressure fluctuations mean?