Anemia — The Impact of Perioperative Transfusion on Postoperative Cognitive Dysfunction
Citation(s)
Behrends M, DePalma G, Sands L, Leung J Association between intraoperative blood transfusions and early postoperative delirium in older adults. J Am Geriatr Soc. 2013 Mar;61(3):365-70. doi: 10.1111/jgs.12143.
Chen QH, Wang HL, Liu L, Shao J, Yu J, Zheng RQ Effects of restrictive red blood cell transfusion on the prognoses of adult patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials. Crit Care. 2018 May 31;22(1):142. doi: 10.1186/s13054-018-2062-5.
Fan YX, Liu FF, Jia M, Yang JJ, Shen JC, Zhu GM, Zhu SH, Li WY, Yang JJ, Ji MH Comparison of restrictive and liberal transfusion strategy on postoperative delirium in aged patients following total hip replacement: a preliminary study. Arch Gerontol Geriatr. 2014 Jul-Aug;59(1):181-5. doi: 10.1016/j.archger.2014.03.009. Epub 2014 Mar 29.
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.
