Devlin NJ, Brooks R EQ-5D and the EuroQol Group: Past, Present and Future. Appl Health Econ Health Policy. 2017 Apr;15(2):127-137. doi: 10.1007/s40258-017-0310-5.
Hansson M, Chotai J, Nordstom A, Bodlund O Comparison of two self-rating scales to detect depression: HADS and PHQ-9. Br J Gen Pract. 2009 Sep;59(566):e283-8. doi: 10.3399/bjgp09X454070.
Henriksson H, Alexandrou C, Henriksson P, Henstrom M, Bendtsen M, Thomas K, Mussener U, Nilsen P, Lof M MINISTOP 2.0: a smartphone app integrated in primary child health care to promote healthy diet and physical activity behaviours and prevent obesity in preschool-aged children: protocol for a hybrid design effectiveness-implementation study. BMC Public Health. 2020 Nov 23;20(1):1756. doi: 10.1186/s12889-020-09808-w.
Ohlsson-Nevo E, Hiyoshi A, Noren P, Moller M, Karlsson J The Swedish RAND-36: psychometric characteristics and reference data from the Mid-Swed Health Survey. J Patient Rep Outcomes. 2021 Aug 4;5(1):66. doi: 10.1186/s41687-021-00331-z.
Olsson SJ, Ekblom O, Andersson E, Borjesson M, Kallings LV Categorical answer modes provide superior validity to open answers when asking for level of physical activity: A cross-sectional study. Scand J Public Health. 2016 Feb;44(1):70-6. doi: 10.1177/1403494815602830. Epub 2015 Sep 21.
Spitzer RL, Kroenke K, Williams JB, Lowe B A brief measure for assessing generalized anxiety disorder: the GAD-7. Arch Intern Med. 2006 May 22;166(10):1092-7. doi: 10.1001/archinte.166.10.1092.
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.
