1. بسم الله الرحمن الرحيم دکتر کورش هلاکوئی نائينی استاد اپيدميولوژی دانشکده بهداشت و انستيتو تحقيقات بهداشتی

2. . براپیدمیولوژی وآمار مقدمه ای براپیدمیولوژی وآمار مقدمه ای

3. تفکر اپیدمیولوژی علم اپیدمیولوژی

4. . HISTORICAL BACKGROUND HISTORICAL BACKGROUND

5. . Epidemiology began with Adam and Eve, both trying to investigate the qualities of the “Forbidden Fruit” Epidemiology began with Adam and Eve, both trying to investigate the qualities of the “Forbidden Fruit”

6. . Hippocrates almost 2400 years ago Whoever wishes to investigate medicine properly should proceed thus: in the first place to consider the seasons of the year, and what effects each of them produces. Then the winds, the hot and the cold, especially such as are common to all countries, and then such as are peculiar to each locality. In the same manner, when one comes into a city to which he is a stranger, he should consider its situation, how it lies as to the winds and the rising of the sun; for its influence is not the same whether it lies to the north or the south, to the rising of to the setting sun. One should consider most attentively the waters which the inhabitants use, whether they be marshy and soft, or hard and running from elevated and rocky situations, and then if and unfit for cooking; and the ground, whether it be naked and deficient in water, saltish or wooded and well watered, and whether it lies in a hollow, confined situation, or is elevated and cold; and the mode in which the inhabitants live, and what are their pursuits, whether they and fond of drinking and eating to excess, and given to indolence, or are fond of exercise and labor. Hippocrates almost 2400 years ago Whoever wishes to investigate medicine properly should proceed thus: in the first place to consider the seasons of the year, and what effects each of them produces. Then the winds, the hot and the cold, especially such as are common to all countries, and then such as are peculiar to each locality. In the same manner, when one comes into a city to which he is a stranger, he should consider its situation, how it lies as to the winds and the rising of the sun; for its influence is not the same whether it lies to the north or the south, to the rising of to the setting sun. One should consider most attentively the waters which the inhabitants use, whether they be marshy and soft, or hard and running from elevated and rocky situations, and then if and unfit for cooking; and the ground, whether it be naked and deficient in water, saltish or wooded and well watered, and whether it lies in a hollow, confined situation, or is elevated and cold; and the mode in which the inhabitants live, and what are their pursuits, whether they and fond of drinking and eating to excess, and given to indolence, or are fond of exercise and labor.

7. . بيماريها و محيط اين فکر که ممکن است بيماريهای انسان با محيط او ارتباط داشته باشند در حدود 2400 سال پيش به وسيله بقراط در رساله آب، هوا و مکان بيان گرديد : اگر خواسته باشی حرفه طبابت را به صورت صحيح به کارگيری بايد اولاٌ از فصول مختلف سال و اثراتی که بر امراض دارند با اطلاع باشی. ثانياٌ انواع بادها: بادهای سرد و گرم ، بادهای اختصاصی هر منطقه و بادهای معروف را بشناسی و ثالثاٌ هنگامی که به يک شهر غريب وارد می شوی بايد ازموقعيت شهر و اينکه در معرض بادها و يا رو به طلوع قرار گرفتن شهر، به سوی شمال يا جنوب يا غروب آفتاب اثرات متفاوتی بر امراض خواهد داشت. بايد کيفيت آب مشروب شهر را بشناسی و بدانی که آيا نرم بوده و از برکه به دست می آيد يا از کوهسار جاری بوده و سخت است و يا اينکه نمک آلود و غير قابل استفاده می باشد. بايد از چگونگی زمين اطلاع حاصل کنی که آيا خشک و بدون علف و يا مرطوب و پردرخت است ، آيا در پستی قرار گرفته و محدود است يا در ارتقاع قرار داشته و سرد است. بايد بدانی که آيا مردم شهر در پی خوردن و نوشيدن و تفريح هستند و يا مردمانی سخت کوش و زحمت کش می باشند. بيماريها و محيط اين فکر که ممکن است بيماريهای انسان با محيط او ارتباط داشته باشند در حدود 2400 سال پيش به وسيله بقراط در رساله آب، هوا و مکان بيان گرديد : اگر خواسته باشی حرفه طبابت را به صورت صحيح به کارگيری بايد اولاٌ از فصول مختلف سال و اثراتی که بر امراض دارند با اطلاع باشی. ثانياٌ انواع بادها: بادهای سرد و گرم ، بادهای اختصاصی هر منطقه و بادهای معروف را بشناسی و ثالثاٌ هنگامی که به يک شهر غريب وارد می شوی بايد ازموقعيت شهر و اينکه در معرض بادها و يا رو به طلوع قرار گرفتن شهر، به سوی شمال يا جنوب يا غروب آفتاب اثرات متفاوتی بر امراض خواهد داشت. بايد کيفيت آب مشروب شهر را بشناسی و بدانی که آيا نرم بوده و از برکه به دست می آيد يا از کوهسار جاری بوده و سخت است و يا اينکه نمک آلود و غير قابل استفاده می باشد. بايد از چگونگی زمين اطلاع حاصل کنی که آيا خشک و بدون علف و يا مرطوب و پردرخت است ، آيا در پستی قرار گرفته و محدود است يا در ارتقاع قرار داشته و سرد است. بايد بدانی که آيا مردم شهر در پی خوردن و نوشيدن و تفريح هستند و يا مردمانی سخت کوش و زحمت کش می باشند.

8. . کاملاٌ تعجب آور است که گفته های بقراط تا دوهزار سال بعد منجر به علم اپیدمیولوژی نگرديد.

9. علت ؟

10. . بقراط در بيان به جای شمارش کنيد از در نظر بگيريد ( (consider—not count استفاده کرده است ( Greenwood, 1934). نمی توان بدون وجود مشاهدات عينی و ثبت شده کمی، پايه ای را برای تحقيقات محققين نسلهای بعدی بوجود بياورد. بقراط در بيان به جای شمارش کنيد از در نظر بگيريد ( (consider—not count استفاده کرده است ( Greenwood, 1934). نمی توان بدون وجود مشاهدات عينی و ثبت شده کمی، پايه ای را برای تحقيقات محققين نسلهای بعدی بوجود بياورد.

11. . John Graunt 1662 The introduction of quantitative methods to Epidemiology John Graunt 1662 The introduction of quantitative methods to Epidemiology

12. . “ NATURAL EXPERIMENTS” William Farr1839 to ascertain the effect of imprisonment of mortality John Snow 1849the demonstration the cholera risk was related to the drinking water supplied by a particular commercial company in London “ NATURAL EXPERIMENTS” William Farr1839 to ascertain the effect of imprisonment of mortality John Snow 1849the demonstration the cholera risk was related to the drinking water supplied by a particular commercial company in London

13. . “ INTERVENTION STUDIES” Lind’s trial 1747of fresh fruit in the treatment of scurvy Jenner’s experiments1796with cowpox vaccination Finlay and Reed1881the demonstration of the mosquito- borne nature of yellow fever Fletcher 1905assessing the protective effect of cured rice against beriberi Goldberger’s1915induction of pellagra by deficient diet “ INTERVENTION STUDIES” Lind’s trial 1747of fresh fruit in the treatment of scurvy Jenner’s experiments1796with cowpox vaccination Finlay and Reed1881the demonstration of the mosquito- borne nature of yellow fever Fletcher 1905assessing the protective effect of cured rice against beriberi Goldberger’s1915induction of pellagra by deficient diet

14. . The history of epidemiologic methodology is largely the history of the development of four ideas: 1- 2- 3- 4- The history of epidemiologic methodology is largely the history of the development of four ideas: 1- 2- 3- 4-

15. . The history of epidemiologic methodology is largely the history of the development of four ideas: 1- Human disease is related to man’s environment; 2- The counting of natural phenomena may be instructive; 3- “ Natural experiments” can be utilized to investigate disease etiology; and 4- Under certain conditions, experiments on man can also be utilized for this purpose The history of epidemiologic methodology is largely the history of the development of four ideas: 1- Human disease is related to man’s environment; 2- The counting of natural phenomena may be instructive; 3- “ Natural experiments” can be utilized to investigate disease etiology; and 4- Under certain conditions, experiments on man can also be utilized for this purpose

16. . Epidemiology ? Epidemiology ?

17. . Epidemiology is derived from the word epidemic (epi=among, demos=people, logos=study) which is a very old word dating back to the 3 rd Century B.C. Epidemiology is derived from the word epidemic (epi=among, demos=people, logos=study) which is a very old word dating back to the 3 rd Century B.C.

18. . 1-That branch of medical science which treats of epidemics (Parkin, 1873) 2- The science of the mass phenomena of infectious disease (Frost, 1927) 3-The study of disease, any disease, as a mass phenomenon (Greenwood, 1934) 4-The study of the distribution and determinants of disease frequency in man (Mac Mahon, 1960) 5-The study of the distribution and determinants of disease and injuries in human population (Mausner, 1974) 1-That branch of medical science which treats of epidemics (Parkin, 1873) 2- The science of the mass phenomena of infectious disease (Frost, 1927) 3-The study of disease, any disease, as a mass phenomenon (Greenwood, 1934) 4-The study of the distribution and determinants of disease frequency in man (Mac Mahon, 1960) 5-The study of the distribution and determinants of disease and injuries in human population (Mausner, 1974)

19. . Epidemiology: The study of the distribution and determinants of health-related states and events in populations, and the application of this study to control health problems (Last, 1985) Epidemiology: The study of the distribution and determinants of health-related states and events in populations, and the application of this study to control health problems (Last, 1985)

20. Epidemiological Sequence Cycle Observing Data Information 12 3-4 5 6 7 8 9 10

25. Epidemiological Sequence Cycle Observing Data Information Intelligence Developing the Hypothesis Testing the Hypothesis 12 3-4 5 6 7 8 9 10

26. . Overview of Epidemiologic Design Strategies Descriptive studies: -Populations (Correlational Studies) - Individuals Case reports Case series Cross-sectional surveys Analytic studies: -Observational Studies Case –control studies Cohort studies (Retrospective & Prospective) - Interventional studies (clinical trials) Overview of Epidemiologic Design Strategies Descriptive studies: -Populations (Correlational Studies) - Individuals Case reports Case series Cross-sectional surveys Analytic studies: -Observational Studies Case –control studies Cohort studies (Retrospective & Prospective) - Interventional studies (clinical trials)

27. .

28. . Case-control Study Exposure Disease ? ? Prospective cohort study Exposure Disease ? ? Retrospective cohort study Exposure Disease ? ? Case-control Study Exposure Disease ? ? Prospective cohort study Exposure Disease ? ? Retrospective cohort study Exposure Disease ? ?

29. General Design of Clinical Trial Reference Population Eligibility Criteria Randomization Study Population Intervention No Intervention Outcome No Outcome Outcome No Outcome

30. Epidemiological Sequence Cycle Observing Data Information Intelligence Developing the Hypothesis Testing the Hypothesis Making Scientific inferences 12 3-4 5 6 7 8 9 10

31. . Framework for the interpretation of an epidemiologic study: A. Is there a valid statistical association? - Chance? - Bias? - Confounding? Framework for the interpretation of an epidemiologic study: A. Is there a valid statistical association? - Chance? - Bias? - Confounding?

32. . B. Can this valid statistical association be judged as cause and effect? Is there: - a strong association? - biologic credibility to the hypothesis? - consistency with other studies? - time sequence compatible? - evidence of a dose-response relationship?

33. Studies Conducting Experimental

34. Epidemiological Sequence cycle Observing Data Information Intelligence Developing the Hypothesis Testing the Hypothesis Making Scientific inferences Conducting Experimental Studies Intervention Evaluation 12 3-4 5 6 7 8 9 10

35. . International Journal of Epidemiology 2007 ________________________________________________________________________ EDITORIAL Epidemiology: a science for justice in health Rodolfo Saracci International Journal of Epidemiology 2007 ________________________________________________________________________ EDITORIAL Epidemiology: a science for justice in health Rodolfo Saracci

36. با تشکر