Fortmann SP, Haskell WL, Wood PD Effects of weight loss on clinic and ambulatory blood pressure in normotensive men. Am J Cardiol. 1988 Jul 1;62(1):89-93.
King AC, Frey-Hewitt B, Dreon DM, Wood PD Diet vs exercise in weight maintenance. The effects of minimal intervention strategies on long-term outcomes in men. Arch Intern Med. 1989 Dec;149(12):2741-6.
Krauss RM, Williams PT, Lindgren FT, Wood PD Coordinate changes in levels of human serum low and high density lipoprotein subclasses in healthy men. Arteriosclerosis. 1988 Mar-Apr;8(2):155-62.
Wood PD, Stefanick ML, Williams PT, Haskell WL The effects on plasma lipoproteins of a prudent weight-reducing diet, with or without exercise, in overweight men and women. N Engl J Med. 1991 Aug 15;325(7):461-6.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
