Baugh CM, Kroshus E, Kiernan PT, Mendel D, Meehan WP 3rd Football Players' Perceptions of Future Risk of Concussion and Concussion-Related Health Outcomes. J Neurotrauma. 2017 Feb 15;34(4):790-797. doi: 10.1089/neu.2016.4585. Epub 2016 Sep 16.
Carson A Concussion, dementia and CTE: are we getting it very wrong? J Neurol Neurosurg Psychiatry. 2017 Jun;88(6):462-464. doi: 10.1136/jnnp-2016-315510. Epub 2017 Apr 10. No abstract available. Erratum In: J Neurol Neurosurg Psychiatry. 2018 Aug;89(8):e7.
Hampshire A, MacDonald A, Owen AM Hypoconnectivity and hyperfrontality in retired American football players. Sci Rep. 2013 Oct 17;3:2972. doi: 10.1038/srep02972.
Kerr ZY, Marshall SW, Harding HP Jr, Guskiewicz KM Nine-year risk of depression diagnosis increases with increasing self-reported concussions in retired professional football players. Am J Sports Med. 2012 Oct;40(10):2206-12. doi: 10.1177/0363546512456193. Epub 2012 Aug 24.
Randolph C, Karantzoulis S, Guskiewicz K Prevalence and characterization of mild cognitive impairment in retired national football league players. J Int Neuropsychol Soc. 2013 Sep;19(8):873-80. doi: 10.1017/S1355617713000805. Epub 2013 Aug 1.
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.
