Related Experiment Video
Updated: Sep 26, 2025
05:59
Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity
Published on: March 7, 2019
6.8K
Measuring Health-Related Quality of Life in Randomised Controlled Trials: Expected and Reported Results Do Not Match
Felicitas Wiedemann1,2, Franz Porzsolt2
1Department of General and Visceral Surgery, Stuttgart, 70176, Germany.
Pragmatic and Observational Research
|April 18, 2022
Summary
Most health-related quality of life studies focus on efficacy under experimental conditions, not real-world effectiveness. This highlights a need to better distinguish between experimental and pragmatic trials for accurate hrQoL assessment.
Area of Science:
- Clinical Research Methodology
- Health Outcomes Research
Background:
- Health-related quality of life (hrQoL) assessment is crucial in clinical research.
- A significant gap exists between treatment efficacy (under experimental conditions) and effectiveness (under real-world conditions).
- Many studies investigating hrQoL as an endpoint may not accurately reflect real-world outcomes.
Purpose of the Study:
- To examine the conflict between efficacy and effectiveness in health-related quality of life (hrQoL) research.
- To determine if hrQoL studies adequately differentiate between experimental and real-world conditions.
- To assess the reporting of pragmatic trial characteristics in hrQoL studies.
Main Methods:
- Analysis of 100 freely available PubMed-listed clinical studies assessing quality of life outcomes (April 2015 - August 2016).
- Evaluation of four key characteristics: study design (RCT vs. non-RCT), pragmatic design description, efficacy vs. effectiveness classification, and inclusion/exclusion criteria.
- Comparison of study characteristics to differentiate between efficacy and effectiveness assessments.
Main Results:
- 91% of studies assessed hrQoL under experimental (RCT) conditions, not real-world conditions.
- The distinction between efficacy and effectiveness was not described in 60% of the studies.
- Only 6% of studies were classified as pragmatic trials, and the difference in inclusion/exclusion criteria was not addressed.
Conclusions:
- hrQoL studies are predominantly conducted as experimental, not pragmatic, trials.
- The meaningfulness of the efficacy versus effectiveness distinction in hrQoL research requires further discussion.
- Current study designs may not adequately capture real-world treatment effects on hrQoL.
Related Concept Videos
01:52Regression Toward the Mean
6.5K
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when...
6.5K
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
185
Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
185
02:07Blind Procedures
12.3K
Ideally, the people who observe and record the children’s behavior are unaware of who was assigned to the experimental or control group, in order to control for experimenter bias. Experimenter bias refers to the possibility that a researcher’s expectations might skew the results of the study. Remember, conducting an experiment requires a lot of planning, and the people involved in the research project have a vested interest in supporting their hypotheses. If the observers knew which...
12.3K
01:13Randomized Experiments
8.0K
The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias.
Simple randomization
Simple...
Simple randomization
Simple...
8.0K
01:20Comparing the Survival Analysis of Two or More Groups
311
Survival analysis is a cornerstone of medical research, used to evaluate the time until an event of interest occurs, such as death, disease recurrence, or recovery. Unlike standard statistical methods, survival analysis is particularly adept at handling censored data—instances where the event has not occurred for some participants by the end of the study or remains unobserved. To address these unique challenges, specialized techniques like the Kaplan-Meier estimator, log-rank test, and...
311
01:11Blinding
3.3K
Blinding is a commonly used method of not telling participants which treatment a subject is receiving. Blinding is a critical part of a randomized control trial or RCT. It reduces the bias that affects the results. In an RCT, blinding is used in the form of a placebo. A placebo effect occurs when untreated subjects falsely believe they have received the treatment and report improved symptoms. A placebo or a dummy treatment is administered to subjects to negate the bias caused by such an effect.
3.3K