![Page 1: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/1.jpg)
Thomas B. Newman, MD, MPH
Andi Marmor, MD, MSEd
October 23, 2008
![Page 2: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/2.jpg)
Outline
Overview and definitions Can screening be bad? Evaluating studies of screening tests
Observational studies of screeningRandomized trials of screening
Conclusion
![Page 3: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/3.jpg)
Outline
Overview and definitions Can screening be bad? Evaluating studies of screening tests
Observational studies of screeningRandomized trials of screening
Conclusion
![Page 4: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/4.jpg)
What is screening?
Common definition: “Testing to detect asymptomatic disease”
Better definition*: “Application of a test to detect a potential disease
or condition in people with no known signs or symptoms of that disease or condition”
*Common screening tests. David M. Eddy, editor. Philadelphia, PA: American College of Physicians, 1991
![Page 5: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/5.jpg)
What is screening?
Common definition: “Testing to detect asymptomatic disease”
Better definition*: “Application of a test to detect a potential disease
or condition in people with no known signs or symptoms of that disease or condition”
*Common screening tests. David M. Eddy, editor. Philadelphia, PA: American College of Physicians, 1991
![Page 6: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/6.jpg)
What is screening?
Common definition: “Testing to detect asymptomatic disease”
Better definition*: “Application of a test to detect a potential disease
or condition in people with no known signs or symptoms of that disease or condition”
“ Condition” includes a risk factor for a disease…
*Common screening tests. David M. Eddy, editor. Philadelphia, PA: American College of Physicians, 1991
![Page 7: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/7.jpg)
Screening Spectrum
Risk factor
Recognized symptomatic disease
Presymptomatic disease
Unrecognized symptomatic disease
Fewer people Easier to demonstrate benefit Less potential for harm
![Page 8: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/8.jpg)
Screening Spectrum
Risk factor
Recognized symptomatic disease
Presymptomatic disease
Unrecognized symptomatic disease
Fewer people Easier to demonstrate benefit Less potential for harm
![Page 9: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/9.jpg)
Issues in Screening for Risk Factors Risk factor treatment disease
Does risk factor predict disease?Does treatment of risk factor reduce disease?
○ Does treatment reduce risk factor?
Test “accuracy” must measure incidence of disease over timeMost measures of test accuracy apply to disease
that is prevalent at the time the test is done
Potential for harm greatest when screening for risk factors!
![Page 10: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/10.jpg)
Screening Spectrum
Risk factor
Recognized symptomatic disease
Presymptomatic disease
Unrecognized symptomatic disease
Fewer people recognized and treated Easier to demonstrate benefit Less potential for harm
![Page 11: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/11.jpg)
Goals of Screening for Presymptomatic Disease Detect disease in earlier stage than would
be detected by symptomsOnly possible if an early detectable phase is
present (latent phase)Only beneficial if earlier treatment is more
effective than later treatment Do this without incurring harm to the
patientNet benefit must exceed net harmLong follow up and RCT may be needed to
prove
![Page 12: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/12.jpg)
Special Case: Screening for Cancer Natural history heterogeneous
Screening test may pick up slower growing or less aggressive cancers
Not all patients diagnosed with cancer will become symptomatic
Diagnosis is subjectiveThere is no gold standard
![Page 13: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/13.jpg)
Outline
Overview and definitions Can screening be bad? Evaluating studies of screening tests
Observational studies of screeningRandomized trials of screening
Conclusion
![Page 14: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/14.jpg)
![Page 15: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/15.jpg)
![Page 16: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/16.jpg)
Possible harms from screening To all To those with negative results To those with positive results
![Page 17: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/17.jpg)
Possible harms from screening To all To those with negative results To those with positive results
![Page 18: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/18.jpg)
![Page 19: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/19.jpg)
Possible harms from screening To all To those with negative results To those with positive results
![Page 20: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/20.jpg)
Source: Funny Times. (1-888-Funnytimes x 476)
![Page 21: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/21.jpg)
Possible harms from screening To all tested To those with negative results To those with positive results
![Page 22: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/22.jpg)
![Page 23: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/23.jpg)
Forces Behind Excessive Screening
Economic Political Health care providers Public/cultural
![Page 24: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/24.jpg)
Forces Behind Excessive Screening
Economic Political Health care providers Public/cultural
![Page 25: Thomas B. Newman, MD, MPH Andi Marmor, MD, MSEd October 23, 2008](https://reader036.vdocuments.us/reader036/viewer/2022062409/5697bf851a28abf838c877b4/html5/thumbnails/25.jpg)
Ad sponsored by Schering: company that
makes interferon.
Continue to Part 2