Diabetes Prevention Program Research Group Within-trial cost-effectiveness of lifestyle intervention or metformin for the primary prevention of type 2 diabetes. Diabetes Care. 2003 Sep;26(9):2518-23.
Feeny D, Furlong W, Boyle M, Torrance GW Multi-attribute health status classification systems. Health Utilities Index. Pharmacoeconomics. 1995 Jun;7(6):490-502. Review.
Ganiats TG, Palinkas LA, Kaplan RM Comparison of Quality of Well-Being scale and Functional Status Index in patients with atrial fibrillation. Med Care. 1992 Oct;30(10):958-64.
Gold M, Franks P, Erickson P Assessing the health of the nation. The predictive validity of a preference-based measure and self-rated health. Med Care. 1996 Feb;34(2):163-77.
Hays RD, Woolley JM The concept of clinically meaningful difference in health-related quality-of-life research. How meaningful is it? Pharmacoeconomics. 2000 Nov;18(5):419-23.
Kaplan RM, Atkins CJ, Timms R Validity of a quality of well-being scale as an outcome measure in chronic obstructive pulmonary disease. J Chronic Dis. 1984;37(2):85-95.
Kaplan RM, Hartwell SL, Wilson DK, Wallace JP Effects of diet and exercise interventions on control and quality of life in non-insulin-dependent diabetes mellitus. J Gen Intern Med. 1987 Jul-Aug;2(4):220-8.
Kaplan RM Decisions about prostate cancer screening in managed care. Curr Opin Oncol. 1997 Sep;9(5):480-6. Review.
Kaplan RM Quality of life assessment for cost/utility studies in cancer. Cancer Treat Rev. 1993;19 Suppl A:85-96. Review.
Kaplan RM Value judgment in the Oregon Medicaid experiment. Med Care. 1994 Oct;32(10):975-88.
Orenstein DM, Kaplan RM Measuring the quality of well-being in cystic fibrosis and lung transplantation. The importance of the area under the curve. Chest. 1991 Oct;100(4):1016-8.
Ries AL, Kaplan RM, Myers R, Prewitt LM Maintenance after pulmonary rehabilitation in chronic lung disease: a randomized trial. Am J Respir Crit Care Med. 2003 Mar 15;167(6):880-8. Epub 2002 Dec 27.
Sieber WJ, David KM, Adams JE, Kaplan RM, Ganiats TG Assessing the impact of migraine on health-related quality of life: An additional use of the quality of well-being scale-self-administered. Headache. 2000 Sep;40(8):662-71.
Ware JE Jr, Gandek B Overview of the SF-36 Health Survey and the International Quality of Life Assessment (IQOLA) Project. J Clin Epidemiol. 1998 Nov;51(11):903-12.
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.