Fennie KP, Bova CA, Williams AB Adjusting and censoring electronic monitoring device data. Implications for study outcomes. J Acquir Immune Defic Syndr. 2006 Dec 1;43 Suppl 1:S88-95.
Walsh JC, Pozniak AL, Nelson MR, Mandalia S, Gazzard BG Virologic rebound on HAART in the context of low treatment adherence is associated with a low prevalence of antiretroviral drug resistance. J Acquir Immune Defic Syndr. 2002 Jul 1;30(3):278-87.
Weiss JJ, Bräu N, Stivala A, Swan T, Fishbein D Review article: adherence to medication for chronic hepatitis C - building on the model of human immunodeficiency virus antiretroviral adherence research. Aliment Pharmacol Ther. 2009 Jul;30(1):14-27. doi: 10.1111/j.1365-2036.2009.04004.x. Epub 2009 Mar 26. Review.
Evaluation of HepCure Toolkit to Improve Harvoni Adherence
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.
