Davison SN, Jhangri GS Impact of pain and symptom burden on the health-related quality of life of hemodialysis patients. J Pain Symptom Manage. 2010 Mar;39(3):477-85. doi: 10.1016/j.jpainsymman.2009.08.008.
Finlayson M, Preissner K, Cho C, Plow M Randomized trial of a teleconference-delivered fatigue management program for people with multiple sclerosis. Mult Scler. 2011 Sep;17(9):1130-40. doi: 10.1177/1352458511404272. Epub 2011 May 11.
Heiwe S, Clyne N, Dahlgren MA Living with chronic renal failure: patients' experiences of their physical and functional capacity. Physiother Res Int. 2003;8(4):167-77.
Murtagh FE, Addington-Hall J, Higginson IJ The prevalence of symptoms in end-stage renal disease: a systematic review. Adv Chronic Kidney Dis. 2007 Jan;14(1):82-99. Review.
Norberg EB, Löfgren B, Boman K, Wennberg P, Brännström M A client-centred programme focusing energy conservation for people with heart failure. Scand J Occup Ther. 2017 Nov;24(6):455-467. doi: 10.1080/11038128.2016.1272631. Epub 2017 Jan 5.
Vanage SM, Gilbertson KK, Mathiowetz V Effects of an energy conservation course on fatigue impact for persons with progressive multiple sclerosis. Am J Occup Ther. 2003 May-Jun;57(3):315-23.
Whitehead AL, Julious SA, Cooper CL, Campbell MJ Estimating the sample size for a pilot randomised trial to minimise the overall trial sample size for the external pilot and main trial for a continuous outcome variable. Stat Methods Med Res. 2016 Jun;25(3):1057-73. doi: 10.1177/0962280215588241. Epub 2015 Jun 19.
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.