Principles and Practice: Introduction to Clinical Trials

Clinical trials are research studies performed in people that are aimed at evaluating a medical, surgical, or behavioral intervention. They are the primary way that researchers find out if a new treatment, like a new drug or diet or medical device (for example, a pacemaker) is safe and effective in people. Often a clinical trial is used to learn if a new treatment is more effective and/or has less harmful side effects than the standard treatment. the intervention can take many forms—medical therapies, behavior changes, or educational materials or websites. The outcome of interest can also be defined in a wide variety of ways—overall survival, disease progression, a body measure (eg, cholesterol level, weight), quality of life or well-being, behavioral change, or other factors. Clinical trials are done to evaluate new approaches to prevention, screening, diagnosis, or treatment. There are many types of clinical research studies and different ways to categorize them. Four common designs are ecological studies, case–control studies, cohort studies, and clinical trials. Clinical trials are research studies in which people volunteer to help find answers to specific health questions. When carefully conducted, they are the safest and fastest way to find new treatments and ways to improve health. Clinical trials are conducted according to a plan, called a protocol, which describes: • the types of patients who may enter the study • the schedules of tests and procedures • the drugs involved • the dosages, or amount of the drug • the length of the study • what the researchers hope to learn from the study [outcomes and endpoints] Clinical trials are usually conducted in a series of steps referred to as Phases. Each Phase has its own purpose and helps researchers answer different questions. Retrospective studies are those in which the outcome has already occurred and thus may only be observational, while prospective studies anticipate a future outcome and may be either interventional or observational. Interventional studies may be either parallel or crossover, and observational studies may be either cross-sectional, case-control or cohort in design. Different Types of Clinical Research? Different types of clinical research are used depending on what the researchers are studying: • Treatment Research • Prevention Research • Diagnostic Research • Screening Research • Quality of Life Research • Genetic studies • Epidemiological studies five different kinds of controls that can be useful circumstance • Placebo concurrent control • Dose-comparison concurrent control • No-treatment concurrent control • Active-treatment concurrent control, and • Historical control The choice of the structural design depends on the specific research questions of interest, characteristics of the disease and therapy, the endpoints, the availability of a control group, and on the availability of funding. For many patients, clinical trials are an important step in accessing newly discovered therapies before they become generally available. It is important to be well informed about the risks and benefits of any treatment before starting. Other clinical trials test ways to find a disease early, sometimes before there are symptoms. Still others test ways to prevent a health problem. A clinical trial may also look at how to make life better for people living with a life-threatening disease or a chronic health problem. Clinical trials sometimes study the role of caregivers or support groups.