Being Clinical – Types of Clinical Studies
A clinical study is a type of research conducted using a clinical trial management system. The trial uses human volunteers, also known as participants, to advance medical knowledge. Clinical trials, also known as interventional and observational studies, are the two main types of clinical studies. Participants in a clinical trial receive specific interventions based on the investigators’ research plan or protocol. Interventions include medical products such as drugs or devices, procedures, or changes in participant behavior such as diet.
Clinical trials go through four stages to test a treatment, determine the proper dosage, and look for side effects. Suppose researchers find a drug or other intervention to be safe and effective after the first three phases. In that case, the FDA approves it for clinical use and continues to monitor its effects.
A new medical approach may be compared to an existing standard, a placebo containing no active ingredients, or no intervention in clinical trials. Some clinical trials compare existing interventions on the market. When researching a new product or approach, it is not always clear whether it will be beneficial, harmful, or no different from existing alternatives. The investigators attempt to determine the intervention’s safety and efficacy by measuring specific outcomes in the participants. But what various studies are there?
Feasibility studies are intended to determine whether the primary research is feasible. They want to know whether patients and doctors are willing to participate and how long it will take to collect and analyze the data. They do not provide an answer to the primary research question of how well a treatment works.
Genetic research aims to improve disorder prediction by identifying and understanding how genes and illnesses may be linked. For example, this research may examine how a person’s genes make them more or less likely to develop a disorder. This could lead to personalized treatments based on a patient’s genetic makeup.
The efficacy or toxicity of a medication is compared in this trial in a group of patients without a control group. The results can be compared to those obtained in previous studies or those published by other researchers. In Phases I and II, uncontrolled trials are expected to investigate tolerated dosing intervals or pharmacokinetic properties of a new drug.
A systematic review critically evaluates and assesses all research studies that address a specific clinical issue. The researchers use a systematic approach to locate, compile, and evaluate a body of literature on a particular topic by employing a set of specific criteria. A systematic review typically includes a description of the findings of the research studies. A quantitative pooling of data, known as a meta-analysis, may also be included in the systematic review.
These are typically conducted during the early stages of a drug’s development, with strict inclusion criteria, to obtain a homogeneous sample of participants, representative only of specific population sub-groups and of limited size. The primary parameters measured are biological, such as the de-obstruction of coronary arteries in patients with myocardial infarction. The studies are typically performed under conditions that differ from routine practice and include an analysis of patients who complete the trial rather than an intention-to-treat analysis. Although it is usually easier to avoid Type-I and Type-II errors in explanatory clinical trials, their power of inference is lower than in pragmatic trials.
In an observational study, researchers evaluate health outcomes in groups of participants using a protocol or research plan. Participants may receive interventions as part of their routine medical care, including medical products such as drugs, devices, or procedures. Still, the investigator does not assign participants to specific interventions.
These randomize groups or individuals to one of two interventions, with outcomes compared at the final endpoint, either by comparing differences in a pre-specified primary outcome at a pre-specified time point or by comparing disease severity between baseline and follow-up.