Guyatt GH, Oxman AD, Schünemann HJ, Tugwell P, Knottnerus A GRADE guidelines: a new series of articles in the Journal of Clinical Epidemiology. J Clin Epidemiol. 2011 Apr;64(4):380-2. doi: 10.1016/j.jclinepi.2010.09.011. Epub 2010 Dec 24.
Higgins JPT, Greens S (editors) Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.
Public Health Agency of Canada (PHAC) National Single Day Food Consumption Report: Analysis of the 24-hour dietary recall data from the Canadian Community Health Survey (CCHS), Cycle 2.2, Nutrition (2004), and assessment for food consumption frequency among Canadians. Available at: http://www.phac-aspc.gc.ca.
Sabaté J, Oda K, Ros E Nut consumption and blood lipid levels: a pooled analysis of 25 intervention trials. Arch Intern Med. 2010 May 10;170(9):821-7. doi: 10.1001/archinternmed.2010.79.
Sievenpiper JL, Dworatzek PD Food and dietary pattern-based recommendations: an emerging approach to clinical practice guidelines for nutrition therapy in diabetes. Can J Diabetes. 2013 Feb;37(1):51-7. doi: 10.1016/j.jcjd.2012.11.001. Epub 2013 Mar 14. Review. Erratum in: Can J Diabetes. 2013 Apr;37(2):135.
U S. Food and Drug Administration (FDA). Guidance for Industry: A Food Labeling Guide (12. Appendix D: Qualified Health Claims). Available at: http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulartoyInformation/LabelingNutrition/ucm064923.htm (Page Last Updated: 08/20/2015).
Nuts in Relation to Markers of Adiposity, Overweight, and Obesity: A Series of Systematic Reviews and Meta-analyses of Randomized Controlled Trials and Prospective Cohort Studies
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.