Hedeker D, Gibbons R Longitudinal Data Analysis. 1st ed. Hoboken, NJ: Wiley, John & Sons, Incorporated; 2006.
Iannotti LL, Lutter CK, Bunn DA, Stewart CP Eggs: the uncracked potential for improving maternal and young child nutrition among the world's poor. Nutr Rev. 2014 Jun;72(6):355-68. doi: 10.1111/nure.12107. Epub 2014 May 7. Review.
Jones KM, Ramirez-Zea M, Zuleta C, Allen LH Prevalent vitamin B-12 deficiency in twelve-month-old Guatemalan infants is predicted by maternal B-12 deficiency and infant diet. J Nutr. 2007 May;137(5):1307-13.
Lofland, J and Lofland, L, 1995. Analyzing Social Settings: A Guide to Qualitative Observation and Analysis. Belmont, CA: Wadsworth.
National Academy of Sciences, Food and Nutrition Board Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington D.C.: National Academies Press; 2001.
Pelto GH, Armar-Klemesu M, Siekmann J, Schofield D The focused ethnographic study 'assessing the behavioral and local market environment for improving the diets of infants and young children 6 to 23 months old' and its use in three countries. Matern Child Nutr. 2013 Jan;9 Suppl 1:35-46. doi: 10.1111/j.1740-8709.2012.00451.x.
Reichertz, Jo (2009) Abduction: The Logic of Discovery of Grounded Theory [39 paragraphs]. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research, 11(1), Art. 13.
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.
