1. Epidemiology & Critical Thinking D. Morse 433 1 st Avenue Tel: 89217 E-mail: dem5@nyu.edudem5@nyu.edu Office Hours: 4:00-5:00 (M & W)

2. Epidemiology & Critical Thinking Syllabus Readings –VitalBook –Required / Non-required readings Examinations –Mid-term 40% (10/14) –Final 60% (cumulative) (12/11) –Format Slides Notes

3. Epidemiology The study of the distribution determinants of disease in human populations

6. Epidemiology in Dentistry Which posterior composite holds up the best over time? Does fluoride prevent caries in older adults? –What about an OTC fluoride mouthrinse? –What about drinking fluoridated drinking water? –What about chlorhexidene rinses to prevent root caries? Does mouthwash use increase the risk of oral cancer? Does periodontal disease increase the risk of heart disease?

7. Past Achievements: Epidemiology & Oral Health Water fluoridation and dental caries Fluoridated toothpaste and dental caries in children Smoking and oral cancer

11. Past Achievements: Epidemiology & Oral Health Water fluoridation and dental caries Fluoridated toothpaste and dental caries in children Smoking and oral cancer

12. Past Achievements: Epidemiology & Oral Health Water fluoridation and dental caries Fluoridated toothpaste and dental caries in children Smoking and oral cancer

13. Epidemiologic Terms Endemic –The usual occurrence of a disease in a given population Epidemic –A meaningful increase in the occurrence of a disease in a given population Pandemic

15. Epidemiologic Terms Validity Generalizability Reliability

16. Statistical vs. Clinical Significance Statistical significance –Relates to the probability that chance is responsible of an observed difference –P-value or confidence interval –Sample size is important –Says nothing about Magnitude of difference Clinical relevance Quality of the study Clinical significance –Relates to whether the findings are important from a clinical standpoint

17. Independent vs. Dependent Variables Independent Variable: Exposure of Interest E  D Dependent Variable: Outcome of Interest E  D

18. Levels of Prevention Primary prevention –prevent the disease Secondary prevention –catch the disease early –prompt treatment Tertiary Prevention –limit disability

19. Generalized Relationship Between Stage of Disease / Ease of Detection / Ease of Cure Stage of Disease LowHigh Ease of CureEase of Detection Difficult Easy

20. Scope of Epidemiology Infectious disease epidemiology Chronic disease epidemiology Occupational epidemiology Clinical epidemiology Molecular epidemiology

21. Laboratory/Animal Model vs. Epidemiologic Research

22. Process of Epidemiologic Reasoning Suspicion of an E  D relationship Hypothesis formation Test E  D hypothesis Rule out alternative explanations –chance –bias –confounding

24. Criteria for Assessing Causality Strength of the association Dose-response relationship Temporal sequence Biologic credibility Consistency of findings across studies

25. Criteria for Assessing Cause-Effect Relationship Strength of the Association Is there a strong E – D relationship? (e.g., smoking and lung cancer) –Less likely due to uncontrolled confounding –Measures of association: OR, RR, RD But, doesn’t imply that a small association can’t be judged as cause and effect

26. Criteria for Assessing Cause-Effect Relationship Dose-Response Relationship Does risk increase with increased exposure? But, may be a threshold effect

27. Relative Risk of Lung Cancer by Level of Cigarette Smoking, Chinese Men Smoking 30-39 Yrs Relative to lifelong nonsmokers

28. Temporal sequence Does the exposure precede the disease? Criteria for Assessing Cause-Effect Relationship

29. Biologic credibility Is there a known biologic basis for the relationship? (e.g., tobacco and lung cancer) But, depends on current state of knowledge Criteria for Assessing Cause-Effect Relationship

30. Consistency of findings across studies Do multiple studies report similar findings regarding the E – D relationship? (e.g., tobacco and lung cancer) Studies can differ by –investigator –methodology –study population Temporal sequence Criteria for Assessing Cause-Effect Relationship