Powers SW, Patton SR, Rajan S A comparison of food group variety between toddlers with and without cystic fibrosis. J Hum Nutr Diet. 2004 Dec;17(6):523-7.
Powers SW, Patton SR A comparison of nutrient intake between infants and toddlers with and without cystic fibrosis. J Am Diet Assoc. 2003 Dec;103(12):1620-5.
Powers SW, Piazza-Waggoner C, Jones JS, Ferguson KS, Daines C, Acton JD Examining clinical trial results with single-subject analysis: an example involving behavioral and nutrition treatment for young children with cystic fibrosis. J Pediatr Psychol. 2006 Jul;31(6):574-81. Epub 2005 Jul 13.
Stark LJ, Powers SW, Jelalian E, Rape RN, Miller DL Modifying problematic mealtime interactions of children with cystic fibrosis and their parents via behavioral parent training. J Pediatr Psychol. 1994 Dec;19(6):751-68.
A Multi-Site Randomized Clinical Trial of Behavioral and Nutrition Treatment Designed to Help Preschoolers With Cystic Fibrosis Optimize Growth
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.
