Karlsson J, Taft C, Sjöström L, Torgerson JS, Sullivan M Psychosocial functioning in the obese before and after weight reduction: construct validity and responsiveness of the Obesity-related Problems scale. Int J Obes Relat Metab Disord. 2003 May;27(5):617-30.
Ko GT The cost of obesity in Hong Kong. Obes Rev. 2008 Mar;9 Suppl 1:74-7. doi: 10.1111/j.1467-789X.2007.00442.x.
Mond JM, Hay PJ, Rodgers B, Owen C, Beumont PJ Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples. Behav Res Ther. 2004 May;42(5):551-67.
Pekkarinen T, Kaukua J, Mustajoki P Long-term weight maintenance after a 17-week weight loss intervention with or without a one-year maintenance program: a randomized controlled trial. J Obes. 2015;2015:651460. doi: 10.1155/2015/651460. Epub 2015 Mar 30.
Spitzer RL, Kroenke K, Williams JB Validation and utility of a self-report version of PRIME-MD: the PHQ primary care study. Primary Care Evaluation of Mental Disorders. Patient Health Questionnaire. JAMA. 1999 Nov 10;282(18):1737-44.
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.