RCTs Flashcards
Advantages-
Advantages of RCTs:
Elimination of Selection Bias: Randomization ensures that participants are assigned to intervention or control groups purely by chance, minimizing selection bias and confounding variables.
WIKIPEDIA
Facilitation of Blinding: Randomization supports blinding (masking) of the identity of treatments from investigators, participants, and assessors, reducing the risk of bias in treatment administration and outcome assessment.
WIKIPEDIA
Statistical Validity: The use of probability theory in RCTs allows for the expression of the likelihood that any difference in outcome between treatment groups is due to chance, enhancing the reliability of the results
gold standard paper
Hariton and lucascio 2018
Randomized controlled trials (RCTs) are prospective studies designed to evaluate the effectiveness of new interventions by minimizing bias and establishing cause-effect relationships. Randomization balances both observed and unobserved participant characteristics between groups, allowing differences in outcomes to be attributed to the intervention. Key design elements include careful selection of populations, interventions, and outcomes, as well as the use of randomization and blinding to further reduce bias. RCTs are typically analyzed using methods like intention-to-treat (ITT), which preserves randomization and minimizes bias. While RCTs are considered the gold standard for evaluating interventions, they are resource-intensive, may face issues with generalizability due to unrepresentative participant samples, and can suffer from participant attrition(loss of ppts)
Despite these challenges, their ability to provide high-quality evidence makes them indispensable in clinical research
disadvantages
High Cost and Time Consumption: RCTs can be expensive and time-consuming to conduct, often requiring significant resources for planning, implementation, and follow-up.
Generalizability Issues: Participants who volunteer for RCTs may not be representative of the broader population, leading to challenges in generalizing the findings to real-world settings. - RCTs rely on good population samples
Ethical Considerations: In some cases, it may be unethical to withhold a potentially beneficial treatment from a control group or to expose participants to a potentially harmful intervention- For example, in HIV prevention trials, providing a placebo instead of antiretroviral therapy has raised significant ethical debates (Macklin, 1999).
example from reading
Davies et al., 2018
The “Breaking Free Online Health and Justice” randomized controlled trial (RCT) evaluates the efficacy of a computer-assisted therapy (CAT) program for substance misuse in a male prison setting, comparing standard treatment alone to standard treatment supplemented with the digital intervention. Strengths of the study include the use of randomization and a control group, comprehensive evaluation of primary (substance misuse) and secondary outcomes (mental health, quality of life), and follow-ups at 3 and 6 months to assess long-term effects.
Comprehensive evaluation refers to looking at multiple aspects of a intervention not just the intervention itself. This is a strength in using RCTs as it helps understand broader implications and improves rigor, minimising the risk of overlooking unintended effects. In this study the evaluation helped determine the interventions range of benefits
However, the study faces limitations such as difficulty with blinding, potential contamination between groups due to interaction within the prison environment, and high attrition rates common in such settings. Despite these challenges, it serves as a strong example of how RCTs can be implemented in complex environments to test innovative interventions, showcasing the method’s rigor and adaptability
example of a bad RCT
Article by Lambert 2024- explains certain issues with RCTs in some fields- for example studying psychodelics
In clinical trials, participants (and the researchers studying them) generally aren’t supposed to know whether they’re getting the actual drug or a placebo, to avoid allowing people’s expectations about a treatment to shape their response to it. Blinding, as this practice is called, is a key component of a randomized controlled clinical trial, or RCT—medicine’s gold standard for demonstrating that a drug actually works. But virtually no one can take a psychedelic drug and not know it.
Some experts believe that unblinding threatens to undermine the entire field of psychedelic research because it means researchers can’t know whether the drugs’ early promise in clinical trials is real or a mirage, driven by the placebo effect and outsize expectations about the power of these drugs. But others argue that RCTs themselves are at fault. To them, psychedelics are exposing long-ignored cracks in our gold standard, especially for testing drugs that act on our minds.
further example 2- negative
Weiss et al., 2000 evaluated the Bezwoda study-
Bezwoda’s study on high-dose chemotherapy with bone marrow transplant for metastatic breast cancer. Bezwoda’s research was later found to involve significant scientific misconduct, including data fabrication and lack of proper randomization. Audits revealed that patient records were incomplete, with many lacking evidence of informed consent or appropriate ethical oversight
this study highlights how RCTs are only the gold standard if rigorous methodology takes place!
highlighted the critical importance of rigorous methodology and ethical standards in conducting RCTs.
WIKIPEDIA
This case underscores how deviations from established research protocols can lead to invalid conclusions, potentially harming patients and undermining public trust in clinical research. It emphasizes the necessity for transparency, proper oversight, and adherence to ethical guidelines to ensure the integrity and reliability of clinical trials.
another example
Robertson 2017-
Family for health intervention- a family based intervention for obesity- one group got normal treatment and the other got the health intervention
positives includes its randomisation
However
attrition rates in the follow ups
It took much longer to recruit=
Differential Follow-up Rates: The study faced varying follow-up rates between groups, with 78.6% in the intervention group and 66.1% in the control group at 12 months. This discrepancy could introduce bias, potentially affecting the reliability of the results.
Recruitment Difficulties: Recruiting the planned number of families took longer than anticipated—24 months instead of the intended 12—highlighting challenges in enrolling participants for RCTs, especially in community settings.
