Kawachi I, Sparrow D, Vokonas PS, Weiss ST Decreased heart rate variability in men with phobic anxiety (data from the Normative Aging Study). Am J Cardiol. 1995 May 1;75(14):882-5.
Lazarus R, Sparrow D, Weiss ST Effects of obesity and fat distribution on ventilatory function: the normative aging study. Chest. 1997 Apr;111(4):891-8.
O'Connor GT, Sparrow D, Segal M, Weiss ST Risk factors for ventilatory impairment among middle-aged and elderly men. The Normative Aging Study. Chest. 1993 Feb;103(2):376-82.
O'Connor GT, Sparrow D, Weiss ST A prospective longitudinal study of methacholine airway responsiveness as a predictor of pulmonary-function decline: the Normative Aging Study. Am J Respir Crit Care Med. 1995 Jul;152(1):87-92.
O'Connor GT, Sparrow D, Weiss ST Normal range of methacholine responsiveness in relation to prechallenge pulmonary function. The Normative Aging Study. Chest. 1994 Mar;105(3):661-6.
Ohman JL Jr, Sparrow D, MacDonald MR New onset wheezing in an older male population: evidence of allergen sensitization in a longitudinal study. Results of the normative aging study. J Allergy Clin Immunol. 1993 Mar;91(3):752-7.
Sparrow D, O'Connor GT, Rosner B, DeMolles D, Weiss ST A longitudinal study of plasma cortisol concentration and pulmonary function decline in men. The Normative Aging Study. Am Rev Respir Dis. 1993 Jun;147(6 Pt 1):1345-8.
Sparrow D, O'Connor GT, Rosner B, Weiss ST Predictors of longitudinal change in methacholine airway responsiveness among middle-aged and older men: the Normative Aging Study. Am J Respir Crit Care Med. 1994 Feb;149(2 Pt 1):376-81.
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.