What is a parallel randomized controlled trial?
A parallel design, also called a parallel group study, compares two or more treatments. Participants are randomly assigned to either group, treatments are administered, and then the results are compared. It is the “gold standard” for phase 3 clinical trials(1). Random assignment is a key element of a parallel design.
Randomized controlled trial: (RCT) A study in which people are allocated at random (by chance alone) to receive one of several clinical interventions. One of these interventions is the standard of comparison or control. The control may be a standard practice, a placebo ("sugar pill"), or no intervention at all.
- Types of Study Designs
- Meta-Analysis. A way of combining data from many different research studies.
- Systematic Review.
- Randomized Controlled Trial.
- Cohort Study (Prospective Observational Study)
- Case-control Study.
- Cross-sectional study.
- Case Reports and Series.
- Ideas, Editorials, Opinions.
- Case control studies are observational because no intervention is attempted and no attempt is made to alter the course of the disease. The goal is to retrospectively determine the exposure to the risk factor of interest from each of the two groups of individuals: cases and controls.
- An open-label trial, or open trial, is a type of clinical trial in which both the researchers and participants know which treatment is being administered. An open-label trial may still be randomized.
Randomized controlled trial: (RCT) A study in which people are allocated at random (by chance alone) to receive one of several clinical interventions. RCTs seek to measure and compare the outcomes after the participants receive the interventions. Because the outcomes are measured, RCTs are quantitative studies.
- A cluster randomised controlled trial is a type of randomised controlled trial in which groups of subjects (as opposed to individual subjects) are randomised. Cluster randomised controlled trials are also known as cluster randomised trials, group-randomised trials, and place-randomized trials.
- Randomised controlled trials are the most rigorous way of determining whether a cause-effect relation exists between treatment and outcome and for assessing the cost effectiveness of a treatment. They have several important features: All intervention groups are treated identically except for the experimental treatment.
- Prospective randomized trials are the gold standard for the evaluation of new treatments. Patients are screened using rigorous eligibility criteria and sometimes are excluded from PRTs because of associated medical conditions or more severe illness.
Of all the many ways research can be conducted, the gold standard level of proof where treatments and therapies are concerned is the Randomized Controlled Trial (RCT). A Randomized Controlled Trial is an experiment or study conducted in such a way that as many sources of bias as possible are removed from the process.
- One of the most important aspects of ground truth is the collection of measurements and observations about the type, size, condition and other physical or chemical properties of importance concerning the materials on the earth's surface that are being sensed remotely.
- Cohen's kappa coefficient (κ) is a statistic which measures inter-rater agreement for qualitative (categorical) items. It is generally thought to be a more robust measure than simple percent agreement calculation, as κ takes into account the possibility of the agreement occurring by chance.
- A negative kappa represents agreement worse than expected, or disagreement. Low negative values (0 to −0.10) may generally be interpreted as “no agreement”. A large negative kappa represents great disagreement among raters. Data collected under conditions of such disagreement among raters are not meaningful.
Updated: 18th October 2018