Bozzetti F, Mariani L Perioperative nutritional support of patients undergoing pancreatic surgery in the age of ERAS. Nutrition. 2014 Nov-Dec;30(11-12):1267-71. doi: 10.1016/j.nut.2014.03.002. Epub 2014 Mar 14. Review.
Coolsen MM, Bakens M, van Dam RM, Olde Damink SW, Dejong CH Implementing an enhanced recovery program after pancreaticoduodenectomy in elderly patients: is it feasible? World J Surg. 2015 Jan;39(1):251-8. doi: 10.1007/s00268-014-2782-x.
Coolsen MM, van Dam RM, van der Wilt AA, Slim K, Lassen K, Dejong CH Systematic review and meta-analysis of enhanced recovery after pancreatic surgery with particular emphasis on pancreaticoduodenectomies. World J Surg. 2013 Aug;37(8):1909-18. doi: 10.1007/s00268-013-2044-3. Review.
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.