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Designing Outcomes & Clinical (DOC) Research: . Case Studies to put it all together, Part I Brian F. Gage, MD, MSc. NSAIDs and Alzheimer’s Dementia (AD).
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Designing Outcomes & Clinical (DOC) Research: Case Studies to put it all together, Part I Brian F. Gage, MD, MSc
NSAIDs and Alzheimer’s Dementia (AD) • A recent meta-analysis of observational studies (M. Etminan BMJ 2003;327) found a pooled RR of AD among NSAID users (e.g. ibuprofen 200+ mg/d) of 0.72, with greater protection in longer-term users. • How would you design the next study in this area?
The Alzheimer's Disease Anti-inflammatory Prevention Trial (ADAPT) • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach http://www.2stopAD.org
Risk of intracranial hemorrhage (ICH) with pseudoephedrine • Phenylpropanolamine is a sympathomimetic amine that was sold in appetite suppressants and cold remedies. • 3 years ago the FDA pulled all products containing phenylpropanolamine off the US market because an increased risk of ICH was found in women who used the drug. • Pseudoephedrine also is a sympathomimetic amine that is popular in cold remedies (e.g. Sudafed). How would you design a study to quantify the effect of pseudoephedrine on ICH?
Quantify the effect of pseudoephedrine on intracranial hemorrhage • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach W. Kernan. NEJM Dec 2000;343
Value of Computed Tomographic (CT) Virtual Colonoscopy • Colonoscopy is recommended each 10 years after age 50 years to screen for colon CA • Patient acceptance of the procedure is poor • How would you evaluate the value of Computed Tomographic (CT) Virtual Colonoscopy?
How would you Determine the Value of CT Virtual Colonoscopy? • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach Computed Tomographic Virtual Colonoscopy to Screen for Colorectal Neoplasia in Asymptomatic Adults. Today’s NEJM 2003.
Genetic risk factors in women • Blood was collected from consenting participants in the Women’s Health Initiative (WHI) study. What study design would you use to determine the genetic factors associated with breast cancer and ischemic heart disease
Genetic factors associated with breast cancer and ischemic heart disease in the WHI • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach A. Pradhan, et al: Inflammatory biomarkers, hormone replacement therapy, and coronary heart disease. 2002 JAMA 288:980
How would you evaluate an oral anti-fungal agent vs. IV amphotericin B (a toxic but effective therapy)? • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach NEJM 2002 Volume 347:2020-2029
Caesarean section and risk of unexplained stillbirth in subsequent pregnancy • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach Lancet 362; Nov 2003, p 1779
Do Carriers for a Rare Genetic Disease Have Adverse Health Consequences? • Design • Time frame • Epidemiologic approach • Subjects • Selection criteria • Sampling design • Variables • Predictor • Confounding • Outcome • Statistical issues • Analytic approach Su Y, Swift M. Mortality rates among carriers of ataxia-telangiectasia mutant alleles.Ann Intern Med. 2000;133:770-8