Javaheri S, Redline S Insomnia and Risk of Cardiovascular Disease. Chest. 2017 Aug;152(2):435-444. doi: 10.1016/j.chest.2017.01.026. Epub 2017 Jan 30.
Johnson KA, Gordon CJ, Chapman JL, Hoyos CM, Marshall NS, Miller CB, Grunstein RR The association of insomnia disorder characterised by objective short sleep duration with hypertension, diabetes and body mass index: A systematic review and meta-analysis. Sleep Med Rev. 2021 Oct;59:101456. doi: 10.1016/j.smrv.2021.101456. Epub 2021 Jan 23.
Kyle SD, Morgan K, Espie CA Insomnia and health-related quality of life. Sleep Med Rev. 2010 Feb;14(1):69-82. doi: 10.1016/j.smrv.2009.07.004. Epub 2009 Dec 4.
Ragnoli B, Pochetti P, Raie A, Malerba M Comorbid Insomnia and Obstructive Sleep Apnea (COMISA): Current Concepts of Patient Management. Int J Environ Res Public Health. 2021 Sep 1;18(17):9248. doi: 10.3390/ijerph18179248.
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.