In other words, they test the effect of a specific exposure or intervention on outcomes rather than simply observing associations between exposures and health outcomes.įor example, treatment trials seek to determine whether a new treatment is superior in effectiveness or toxicity compared to an existing therapy. In contrast to observational studies, clinical trials are interventional in design. For example, clinical trials are conducted to obtain evidence for health care decisions by disentangling the effects of treatment from the underlying disease or other factors that may influence outcomes (e.g., age) that cannot be randomly assigned. Thus, when possible it is preferable to study exposures and health outcomes in an experimental, non-randomized setting (i.e., a clinical trial) in order to obtain more precise estimates of effect. Observational study designs can provide some insight into associations between exposures and health outcomes but can be confounded by factors that may influence the outcomes of interest and exposure (confounding variables), and in some cases, provide no information on causality or risk. test a treatment or preventive strategy for a disease or health endpoint that has already been demonstrated as efficacious in clinical trials.determine whether a hypothesized factor (e.g., exposure, risk factor) is valid or whether a novel factor is associated with an outcome of interest.assess associations between exposures/risk factors and health outcomes without assigning participants to specific interventions.investigate pathogenesis and processes underlying diseases or health endpoints.While observational designs provide less evidence for causal inference relative to experimental designs, they often have the benefit of being less costly and more feasible to conduct, as they do not require the introduction of an intervention. Observational studies generally collect data on participant characteristics and health status without directly manipulating variables in participants’ natural environment. In observational studies, investigators measure exposure(s) that are suspected to influence the risk of disease, or related outcomes/health endpoints. Observational studies are typically cross-sectional in design and assess associations between exposures/risk factors and health outcomes without assigning participants to specific interventions. On the other hand, interventional studies involve giving people specific treatments, including new drugs or medical devices. Observational studies observe what happens to a particular group of people. Research using human subjects falls into two broad categories: observational studies and interventional studies. Clinical trials help to determine if the new drug or therapy helps to cure or prevent diseases. The participants can be healthy individuals or patients with a certain disease. It is conducted by pharmaceutical companies, universities, government agencies, and medical institutions.Ĭlinical trials are studies done in clinical research. Clinical research is a branch of healthcare science that investigates the effectiveness or safety of a medical treatment in humans.