Randomized Controlled Clinical Intervention Study (RCT)

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A Randomized Controlled Clinical Intervention Study (RCT) is a controlled clinical intervention study (of a experimental medical intervention) that is a randomized controlled experiment where intervention subjects are randomly assigned to clinical therapy groups.




  • (Wikipedia, 2021) ⇒ https://en.wikipedia.org/wiki/Clinical_trial#Types Retrieved:2021-12-28.
    • Clinical trials are classified by the research objective created by the investigators.
      • In an observational study, the investigators observe the subjects and measure their outcomes. The researchers do not actively manage the study.
      • In an interventional study, the investigators give the research subjects an experimental drug, surgical procedure, use of a medical device, diagnostic or other intervention to compare the treated subjects with those receiving no treatment or the standard treatment. Then the researchers assess how the subjects' health changes.
    • Trials are classified by their purpose. After approval for human research is granted to the trial sponsor, the U.S. Food and Drug Administration (FDA) organizes and monitors the results of trials according to type:
      • Prevention'' trials look for ways to prevent disease in people who have never had the disease or to prevent a disease from returning. These approaches may include drugs, vitamins or other micronutrients, vaccines, or lifestyle changes.
      • Screening trials test for ways to identify certain diseases or health conditions.
      • Diagnostic trials are conducted to find better tests or procedures for diagnosing a particular disease or condition.
      • Treatment trials test experimental drugs, new combinations of drugs, or new approaches to surgery or radiation therapy.
      • Quality of life trials (supportive care trials) evaluate how to improve comfort and quality of care for people with a chronic illness.
      • Genetic trials are conducted to assess the prediction accuracy of genetic disorders making a person more or less likely to develop a disease.
      • Epidemiological trials have the goal of identifying the general causes, patterns or control of diseases in large numbers of people.
      • Compassionate use trials or expanded access trials provide partially tested, unapproved therapeutics to a small number of patients who have no other realistic options. Usually, this involves a disease for which no effective therapy has been approved, or a patient who has already failed all standard treatments and whose health is too compromised to qualify for participation in randomized clinical trials. Usually, case-by-case approval must be granted by both the FDA and the pharmaceutical company for such exceptions. * Fixed trials consider existing data only during the trial's design, do not modify the trial after it begins, and do not assess the results until the study is completed. * Adaptive clinical trials use existing data to design the trial, and then use interim results to modify the trial as it proceeds. Modifications include dosage, sample size, drug undergoing trial, patient selection criteria and "cocktail" mix. Adaptive trials often employ a Bayesian experimental design to assess the trial's progress. In some cases, trials have become an ongoing process that regularly adds and drops therapies and patient groups as more information is gained. The aim is to more quickly identify drugs that have a therapeutic effect and to zero in on patient populations for whom the drug is appropriate.
    • Clinical trials are conducted typically in four phases, with each phase using different numbers of subjects and having a different purpose to construct focus on identifying a specific effect.



  • (Suvarnaamesh, 2018) ⇒ Viraj R. Suvarnaamesh. (2018). “Real World Evidence (RWE) - Are We (RWE) Ready?. ” Perspectives in Clinical Research, 9(2).
    • QUOTE: ... What is real-world evidence? Obviously, evidence that is generated or exists in the real world. Why is it important? Typically, evidence generated within a randomized controlled clinical trial (RCT) is considered higher than that in the real world. Where hypotheses are generated double blinding and randomization (which ensures every patient has an equal chance of being allocated to treatment A or treatment B) are ways of ensuring that comparable cohorts are created, and bias is minimized to the extent possible. Naturally, a hypothesis can be tested within an RCT. However, there are limitations of an RCT. For example, in an RCT, there are inclusion and exclusion criteria. These eligibility criteria ensure that a homogeneous and representative sample is collected. However, in the real world, can any patient be excluded? Data from an RCT can only be extrapolated to the kind of patients who were eligible for the RCT. Hence, there are limitations of generalizability. Moreover, that is where real-world evidence comes in, to supplement data from RCTs, and hopefully bridge the gap between the controlled environment of an RCT and the harsh realities of the real world. (Nallamothu et al., 2008) ...

      ... In an ideal world, both the RCT and real-world evidence coexist and one can even do large simple studies, where the two elements are blended such that the results do mirror what happens in the real world. Such hybrid, efficacy-effectiveness studies can help in advancing a closer correlation to the real world within a clinical development program. However, real-world studies are fraught with their own limitations. Can one randomize in the real world? What about retrospective analyses of databases (electronic medical records) in the real world or comparative effectiveness research? They have their uses viz., in comparing the cost-effectiveness of two regimens in the real world, beyond the rigors of an RCT. ...


  • (Nallamothu et al., 2008) ⇒ Brahmajee K. Nallamothu, Rodney A. Hayward, and Eric R. Bates. (2008). “Beyond the Randomized Clinical Trial: The Role of Effectiveness Studies in Evaluating Cardiovascular Therapies.” Circulation 118, no. 12
    • QUOTE: ... It would be desirable to rely solely on RCTs to guide clinical practice, but this is simply not feasible. At the root of the problem is the fact that RCTs are typically restricted to evaluating specific discrete interventions one at a time. This restriction limits their ability to (1) directly assess complex interactions within a study arm (ie, interactions between different blood pressure medicines used to obtain tight blood pressure control), (2) continuous relationships (such as what blood pressure or cholesterol levels are optimal), and (3) whether the benefits or harm of a treatment are drug-specific or mechanistic. As a result, traditional RCTs focus more on evaluating the efficacy of simple therapies like drugs and less on the delivery of care. ...

      ... Furthermore, even within these highly selected patients there can be heterogeneity in the extent of benefit found with a therapy. For example, scenarios may exist where an average treatment effect favors a therapy because of its benefit to a few high-risk patients, although most individuals in the study gain little from it. ...

      ... Finally, RCTs often require enormous resource investments and may be inherently limited in their ability to investigate certain issues for logistical or ethical reasons. The recently completed Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial, which compared optimal medical therapy with and without percutaneous coronary intervention (PCI) in 2287 patients,4 resulted in nearly $60 million in total costs shared by both public and private sponsors (personal communication, William E. Boden, MD, 2008). ...