Herzig SJ, Howell MD, Ngo LH, Marcantonio ER Acid-suppressive medication use and the risk for hospital-acquired pneumonia. JAMA. 2009 May 27;301(20):2120-8. doi: 10.1001/jama.2009.722.
Lin PC, Chang CH, Hsu PI, Tseng PL, Huang YB The efficacy and safety of proton pump inhibitors vs histamine-2 receptor antagonists for stress ulcer bleeding prophylaxis among critical care patients: a meta-analysis. Crit Care Med. 2010 Apr;38(4):1197-205. doi: 10.1097/CCM.0b013e3181d69ccf.
Pingleton SK, Hadzima SK Enteral alimentation and gastrointestinal bleeding in mechanically ventilated patients. Crit Care Med. 1983 Jan;11(1):13-6.
Pisegna JR Pharmacology of acid suppression in the hospital setting: focus on proton pump inhibition. Crit Care Med. 2002 Jun;30(6 Suppl):S356-61. Review.
Raff T, Germann G, Hartmann B The value of early enteral nutrition in the prophylaxis of stress ulceration in the severely burned patient. Burns. 1997 Jun;23(4):313-8.
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.