Geyer M, Guller U, Beglinger C Carbon dioxide insufflation in routine colonoscopy is safe and more comfortable: results of a randomized controlled double-blinded trial. Diagn Ther Endosc. 2011;2011:378906. doi: 10.1155/2011/378906. Epub 2011 Jun 15.
Leung FW, Leung JW, Mann SK, Friedland S, Ramirez FC The water method significantly enhances patient-centered outcomes in sedated and unsedated colonoscopy. Endoscopy. 2011 Sep;43(9):816-21. doi: 10.1055/s-0030-1256407. Epub 2011 May 24.
Leung FW, Leung JW, Siao-Salera RM, Mann SK, Jackson G The water method significantly enhances detection of diminutive lesions (adenoma and hyperplastic polyp combined) in the proximal colon in screening colonoscopy - data derived from two RCT in US veterans. J Interv Gastroenterol. 2011 Apr;1(2):48-52.
Ramirez FC, Leung FW A head-to-head comparison of the water vs. air method in patients undergoing screening colonoscopy. J Interv Gastroenterol. 2011 Jul;1(3):130-135. Epub 2011 Jul 1.
Wong JC, Yau KK, Cheung HY, Wong DC, Chung CC, Li MK Towards painless colonoscopy: a randomized controlled trial on carbon dioxide-insufflating colonoscopy. ANZ J Surg. 2008 Oct;78(10):871-4. doi: 10.1111/j.1445-2197.2008.04683.x.
Water Exchange Versus Carbon Dioxide Insufflation to Improve Colonoscopy Screening - a Randomized Controlled Trial
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.
