Jagger, C , Matthews, R., Spiers, N., Brayne, C., Comas - Herrera, A., Robinson, T., . . . Croft, P. (2006). Compression or expansion of disability?: forecasting future disability levels under changing patterns of diseases: King's Fund.
Klit J, Jacobsen S, Rosenlund S, Sonne-Holm S, Troelsen A Total knee arthroplasty in younger patients evaluated by alternative outcome measures. J Arthroplasty. 2014 May;29(5):912-7. doi: 10.1016/j.arth.2013.09.035. Epub 2013 Oct 1.
Lungu E, Desmeules F, Dionne CE, Belzile EL, Vendittoli PA Prediction of poor outcomes six months following total knee arthroplasty in patients awaiting surgery. BMC Musculoskelet Disord. 2014 Sep 8;15:299. doi: 10.1186/1471-2474-15-299.
Patel A, Pavlou G, Mújica-Mota RE, Toms AD The epidemiology of revision total knee and hip arthroplasty in England and Wales: a comparative analysis with projections for the United States. A study using the National Joint Registry dataset. Bone Joint J. 2015 Aug;97-B(8):1076-81. doi: 10.1302/0301-620X.97B8.35170.
Portney, L , & Watkins, M. (2009). Foundations of Clinical Research: Applications to Practice. London: Pearson/Prentice Hall, 2009.
Retrospective Analysis of Patient Outcome Questionnaire Following Primary Knee Replacement
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.