Brummett BH, Barefoot JC, Vitaliano PP, Siegler IC Associations among social support, income, and symptoms of depression in an educated sample: the UNC Alumni Heart Study. Int J Behav Med. 2003;10(3):239-50. doi: 10.1207/s15327558ijbm1003_04.
Brummett BH, Siegler IC, McQuoid DR, Svenson IK, Marchuk DA, Steffens DC Associations among the NEO Personality Inventory, Revised and the serotonin transporter gene-linked polymorphic region in elders: effects of depression and gender. Psychiatr Genet. 2003 Mar;13(1):13-8. doi: 10.1097/00041444-200303000-00002.
Costa PT Jr, Herbst JH, McCrae RR, Siegler IC Personality at midlife: stability, intrinsic maturation, and response to life events. Assessment. 2000 Dec;7(4):365-78. doi: 10.1177/107319110000700405.
McPherson RS, Feaganes JR, Siegler IC Measurement of dietary intake in the UNC Alumni Heart Study. University of North Carolina. Prev Med. 2000 Jul;31(1):56-67. doi: 10.1006/pmed.2000.0679.
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.
