Cardiovascular Diseases — Cardiovascular Risk Factors in United States Adolescents and Adults
Citation(s)
Basu S, Landis JR Model-based estimation of population attributable risk under cross-sectional sampling. Am J Epidemiol. 1995 Dec 15;142(12):1338-43.
Flegal KM, Harlan WR, Landis JR Secular trends in body mass index and skinfold thickness with socioeconomic factors in young adult men. Am J Clin Nutr. 1988 Sep;48(3):544-51.
Flegal KM, Harlan WR, Landis JR Secular trends in body mass index and skinfold thickness with socioeconomic factors in young adult women. Am J Clin Nutr. 1988 Sep;48(3):535-43.
Landis JR, Flegal KM A generalized Mantel-Haenszel analysis of the regression of blood pressure on blood lead using NHANES II data. Environ Health Perspect. 1988 Jun;78:35-41.
Miller ME, Davis CS, Landis JR The analysis of longitudinal polytomous data: generalized estimating equations and connections with weighted least squares. Biometrics. 1993 Dec;49(4):1033-44.
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.
