Gruffydd-Jones K, Loveridge C The 2010 NICE COPD Guidelines: how do they compare with the GOLD guidelines? Prim Care Respir J. 2011 Jun;20(2):199-204. doi: 10.4104/pcrj.2011.00011.
Langsetmo L, Platt RW, Ernst P, Bourbeau J Underreporting exacerbation of chronic obstructive pulmonary disease in a longitudinal cohort. Am J Respir Crit Care Med. 2008 Feb 15;177(4):396-401. Epub 2007 Nov 29.
Leidy NK, Vernon M Perspectives on patient-reported outcomes : content validity and qualitative research in a changing clinical trial environment. Pharmacoeconomics. 2008;26(5):363-70.
Mannino DM, Gagnon RC, Petty TL, Lydick E Obstructive lung disease and low lung function in adults in the United States: data from the National Health and Nutrition Examination Survey, 1988-1994. Arch Intern Med. 2000 Jun 12;160(11):1683-9.
Roche N, Gaillat J, Garre M, Meunier JP, Lemaire N, Bendjenana H Acute respiratory illness as a trigger for detecting chronic bronchitis in adults at risk of COPD: a primary care survey. Prim Care Respir J. 2010 Dec;19(4):371-7. doi: 10.4104/pcrj.2010.00042.
Ware JE Jr, Sherbourne CD The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care. 1992 Jun;30(6):473-83.
Wilt TJ, Niewoehner D, MacDonald R, Kane RL Management of stable chronic obstructive pulmonary disease: a systematic review for a clinical practice guideline. Ann Intern Med. 2007 Nov 6;147(9):639-53. Review.
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.