Mak WY, Lung PFC, Hart A In Patients With Perianal Crohn's Fistulas, What Are the Outcomes When 'Radiological Healing' Is Achieved? Does Radiological Healing of Perianal Crohn's Fistulas Herald the Time Point for Stopping a Biologic? J Crohns Colitis. 2017 Dec 4;11(12):1506. doi: 10.1093/ecco-jcc/jjx094.
Ng SC, Plamondon S, Gupta A, Burling D, Swatton A, Vaizey CJ, Kamm MA Prospective evaluation of anti-tumor necrosis factor therapy guided by magnetic resonance imaging for Crohn's perineal fistulas. Am J Gastroenterol. 2009 Dec;104(12):2973-86. doi: 10.1038/ajg.2009.509. Epub 2009 Sep 15.
Tozer PJ, Burling D, Gupta A, Phillips RK, Hart AL Review article: medical, surgical and radiological management of perianal Crohn's fistulas. Aliment Pharmacol Ther. 2011 Jan;33(1):5-22. doi: 10.1111/j.1365-2036.2010.04486.x. Epub 2010 Oct 29. Review.
Wei SC Differences in the public medical insurance systems for inflammatory bowel disease treatment in Asian countries. Intest Res. 2016 Jul;14(3):218-23. doi: 10.5217/ir.2016.14.3.218. Epub 2016 Jun 27.
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.
