George Jelinek shared some valuable information in his post - The critical part of the jigsaw of the diet in MS is Professor Swank’s work - which touched on the nature of clinical trials.

When we think of clinical trials, the image of pharma-sponsored drug trials immediately come to mind.  Perhaps this is because we hear most about drugs in trials, drugs which have been tested for use in MS, and drugs which receive that important FDA approval before hitting the market.  But drug trials are not the only types of clinical trials.

Clinical trials fall into several categories, including:

Treatment trials: These studies test new treatments for diseases or conditions. These treatments can include experimental treatments, new drugs, new combinations of drugs, or new approaches to surgery or radiation therapy.

A treatment trial may also study "off-label" uses for an existing FDA-approved treatment. Off-label means the drug is being use as a treatment for a different condition (or indication) than the drug was originally approved to treat.

Screening trials: These studies test for the best ways to detect diseases and conditions.  These trials involve participants who have no symptoms of the condition and can be done on the general population. Or they involve a group of people who have a 'higher than normal' risk of developing a disease or condition.

Prevention trials: Prevention trials look for better ways to prevent disease in people who have never had the specific disease being studied or to prevent a disease from returning. Approaches to prevention may include lifestyle changes, vaccines, vitamins, minerals, or medicines.  As with screening trials, prevention trials can be carried out on the general population, or on a specific high risk group.

Diagnostic trials: These studies are conducted to find better tests or procedures for diagnosing a particular disease or condition.  Diagnostic trials usually involve people who already have signs of the disease or condition.

Quality of Life trials (or Supportive Care trials): These studies explore how your treatment or illness affects you and often seek ways to improve comfort and the quality of life for individuals with a chronic illness.  Many trials include a quality of life assessment as part of the main trial, which may be conducted separately as a 'quality of life study'.

Epidemiology studies: These trials look at causes and patterns of disease, for instance whether a particular factor causes cancer or not, and are primarily observational.  There are three types of observational studies - cohort studies, case control studies and cross sectional studies.  (visit CancerHelpUK for more information)

More specific types of treatment trials:

Pilot studies: Pilot studies (or feasibility studies) are small-scale versions of larger treatment trials. The format is the same but involve only a small number of people and can be completed more quickly.  Not all trials need a pilot study first, but they useful in testing the trial design (protocol) so that investigators can make changes before the larger trial begins.