Epidemiologi Departemen Epidemiologi Fakultas Kesehatan Masyarakat Universitas Indonesia

Definisi (1) Tidak ada definisi tunggal Epidemiologi Dari bahasa Greek. Epi = atas, pada, demos = penduduk, logi = studi Studi distribusi dan determinan peristiwa kesehatan dalam populasi manusia.

Definisi (2) Hirsch (1883) Frost (1927) Suatu gambaran kejadian, distribusi, dan tipe penyakit manusia, ….. Frost (1927) Ilmu fenomena masal penyakit infeksius, atau seperti riwayat alamiah penyakit infeksius … suatu ilmu induktif yang tidak hanya mendeskripsikan distribusi penyakit, melainkan kesesuaiannya dalam suatu filosofi yang konsisten

Definisi (3) Greenwood ( 1934) Lilienfeld (1957) Epidemiologi adalah studi penyakit sebagai fenomena massal Lilienfeld (1957) Epidemiologi boleh didefinisikan sebagai studi distribusi suatu penyakit atau kondisi dalam populasi dan faktor yang mempengaruhi distribusi ini

Definisi (4) Taylor (1963) McMahon, Pugh, dan Ipsen (1970) Studi kesehatan atau penyakit dalam populasi McMahon, Pugh, dan Ipsen (1970) Studi distribusi dan determinan frekuensi penyakit pada manusia … distribusi … (epidemiologi deskriptif) dan determinan dari distribusi yang tercatat (epidemiologi analitik)

Epidemiology Defined Greek roots epi = upon (as in “epidermis”) demos = the people (as in demography) ology = “to speak of”, “to study” Literally - “study of epidemics” Modern definitions of epidemiology refer to distributions in populations (statistical) determinants (pathophysiological, environmental, behavioral) control of health problems (biological, social, economic, political, administrative, legal) Gerstman Chapter 1

Public Health Defined Definitions of public health refer to organized effort (activity) reduction of morbidity & mortality improvements in health Main public health competency areas epidemiology biostatistics health administration behavioral environmental health science Gerstman Chapter 1

Epidemiology compared to… … medicine Main unit of concern in epi  population Main unit of concern in medicine  individual … public health Epidemiology  “study of” Public health  “organized effort” Epi said to be “methodologic backbone” of public health Gerstman Chapter 1

Definisi (5) Suatu ilmu dasar dari kedokteran pencegahan dan kesehatan masyarakat yang mempelajari: Penyakit (atau status kesehatan) Frekuensi (enumerasi jumlah yang ada atau tingkat perkembangan dalam periode waktu spesifik) Determinan (faktor yang mempengaruhi distribusi) Metode (proses yang dilakukan untuk mendeskripsikan frekuensi dan distribusi, rasional ilmiah yang digunakan untuk menentukan kausal distribusi penyakit dalam populasi Populasi (populasi manusia tertentu)

Epidemiologi  Ilmu dasar semua aspek kesehatan masyarakat: (1) Penyakit infeksi Penyakit kronis Cedera intensional dan tidak intensional Kesehatan mental Nutrisi

Epidemiologi  Ilmu dasar semua aspek kesehatan masyarakat: (2) Pendidikan dan promosi kesehatan Perencanaan kesehatan Administrasi kesehatan masyarakat Pelayanan pengobatan medis

Ruang lingkup Definisi penyakit Kejadian penyakit Penyebab penyakit Keluaran penyakit Pengelolaan penyakit dan pencegahan penyakit

Aktivitas epidemiologi (1) Pengumpulan dan analisis pencatatan vital (kelahiran dan kematian) Pengumpulan dan analisis data morbiditas dari rumah sakit, lembaga kesehatan, klinik, dokter dan industri Pemantauan penyakit dan masalah kesehatan komunitas yang lain

Aktivitas epidemiologi (2) Investigasi kejadian luar biasa yang mengarahkan program pemberantasan atau pencegahan epidemik dan masalah kesehatan komunitas yang lain Merancang dan melaksanakan penelitian kesehatan Merancang dan melaksanakan registrasi kesehatan untuk masalah yang menjadi perhatian seperti: cacat lahir, insidens kanker, atau penggunaan napza

Aktivitas epidemiologi (3) Skrining (penapisan) untuk penyakit Penilaian efektivitas keberadaan pengobatan yang baru Mendeskripsikan riwayat alamiah penyakit Identifikasi individu atau kelompok pada populasi umum terhadap peningkatan risiko perkembangan penyakit tertentu

Aktivitas epidemiologi (4) Identifikasi keterkaitan etiologi penyakit Identifikasi masalah kesehatan masyarakat dan pengukuran besar distribusi, frekuensi, atau dampak pada kesehatan masyarakat

Aktivitas epidemiologi (5) Penilaian program kesehatan Menyediakan data yang diperlukan untuk perencanaan kesehatan atau pembuatan keputusan oleh badan administrasi kesehatan atau pembuat kebijakan kesehatan

Who is an epidemiologist ? A professional who strives to study and control the factors that influence the occurrence of disease or health-related conditions and events in specified populations and societies, has an experience in population thinking and epidemiologic methods, and is knowledgeable about public health and causal inference in health (Porta M, Last J, Greenland S. A Dictionary of Epidemiology, 2008)

Epidemiologists are required to have some knowledge of: • Public health: because of the emphasis on disease prevention •Clinical medicine: because of the emphasis on disease classification and diagnosis (numerators)  • Pathophysiology: because of the need to understand basic biological mechanisms in disease (natural history) • Biostatistics: because of the need to quantify disease frequency and its relationships to antecedents (denominators, testing hypotheses) • Social sciences: because of the need to understand the social context in which disease occurs and presents (social determinants of health phenomena) 19

§1.4 Selected Historical Figures and Events Understanding medical history is an important part of epidemiology This section divided into three eras 400BC – 1850 1850 - 1900 Twentieth century epi

Historical Figures & Events 400BC – 1850 Hippocrates (400BCE) Age of enlightenment (17th & 18th centuries) John Graunt (1620 – 1674) 1850 -1900 John Snow (1813 – 1858) Germ Theory (mid 19th century) Twentieth century epi Modern epidemiology Gerstman Chapter 1

Sejarah perkembangan epidemiologi Ahli epidemiologi pertama Hippocrates 460 – 377 SM Ahli Epidemiologi yang pertama Menjelaskan terjadinya penyakit dari dasar yang rasional Buku yang ditulis: Epidemic I, Epidemic II, On Airs, Waters, and Places Memperkenalkan istilah epidemic dan endemic

The First Epidemiologists Hippocrates 460 B. C. to 377 B.C. attempted to explain disease occurrence on a rational basis instead of from a supernatural view point Three major books Epidemic I Epidemic II On Airs, Waters, and Places

Hippocrates (1) Recognized the association of various diseases with environmental factors place water conditions climate eating habits housing

Hippocrates (2) Introduced epidemic endemic

Hippocrates (3) Theory about the cause of disease personal observation Greek thinking Disease is the imbalance of body humors phlegm blood yellow bile, black bile

Sejarah perkembangan epidemiologi Galen 129 – 199 M Ahli bedah tentara romawi Bapak “Fisiologi Eksperimental” Faktor Prokatartik (cara hidup orang) dan temperamen mempengaruhi kesehatan dan penyakit Pengaruh lingkungan (geografi dan iklim)  miasma (istilah umum untuk partikel dalam udara) Malaria  udara buruk Teori miasma

Galen (1) 129 - 199 A.D. Father of experimental physiology Health and Disease influenced by Procataritic factors the way of life a person led life style Temperament the innate qualities of the body personality

Galen (2) Disease caused by Miasma particles in the air from sources waste stagnant water decaying animals theory used to explain the great plague epidemic in Europe

Sejarah perkembangan epidemiologi Age of enlightenment (17th & 18th centuries) Thomas Sydenham (1624 – 1689) “Hippocrates Inggris” Bapak Epidemiologi Atmosfer mengakibatkan perubahan konstitusi epidemik

Thomas Sydenham (1) 1624 - 1689 Father of Epidemiology insisted that observation should have precedence over theory in the study of the natural history of disease

Demographic Approach (pp. 12–14) John Graunt (1620 – 1674)

Sejarah perkembangan epidemiologi DEMOGRAPHIC APPROACH Kelahiran vital statistik John Graunt Analisis data mortalitas dalam tahun 1662 Melakukan kuantifikasi yang pertama dari pola kelahiran, kematian dan kejadian penyakit Mencatat perbedaan laki-laki dan perempuan, kematian bayi yang tinggi, perbedaan urban-rural, dan variasi musiman

Demographic Approach 17th Century Life Table Age % surviving 6 64 16 40 26 25 36 46 10 56 60 3 76 1 80 John Graunt (1620–74) Gerstman Chapter 1

Life Table of Deaths in London Age Deaths Survivors -- 100 6 36 64 16 24 40 26 15 25 9 46 10 56 4 66 3 76 2 1 80 Source: Graunt’s Observations 1662

Graunt’s Observations Excess of male births High infant mortality Seasonal variation in mortality

Sejarah perkembangan epidemiologi Willian Farr Melakukan pengumpulan data secara sistematik dan statistik kematian di Inggris Bapak Statistik vital moderen dan surveilens Memperluas analisis data morbidtas dan mortalitas epidemiologi Melihat efek status perkawinan, pekerjaan dan ketinggian

Sejarah perkembangan epidemiologi Konsep kontagion dan Teori germ penyakit Hieronymous Frascastorius (1478 – 1553) Sastrawan dan dokter dari Italia Penyakit disebabkan oleh “germ” Penyakit ditransmisikan dari orang ke orang melalui suatu partikel yang sangat kecil Igmatz Semmelweis (1818 – 1865) Ahli Obstetri dari Hungaria Demam nifas dapat direduksi jika para dokter mencuci tangan sebelum menolong persalinan

Downloaded from: StudentConsult (on 29 August 2009 12:10 AM) © 2005 Elsevier

Downloaded from: StudentConsult (on 29 August 2009 12:10 AM) © 2005 Elsevier

Sejarah perkembangan epidemiologi Edward Jenner Mendukung teori Fracastorius Menerima teori germ penyakit Penemu vaksin cacar (akhir tahun 1700) Louis Pasteur Berkontribusi dalam menguatkan teori germ penyakit dengan mendemonstrasikan efektivitas imunisasi pada pencegahan rabies dalam tahun 1885 Belum mampu mengisolasi virus rabies  menghalau teori miasma

Sejarah perkembangan epidemiologi Studi epidemiologi klasik awal James Lind Melakukan studi epidemiologi ekperimen pada etiologi dan pengobatan scurvy (1753) Makan jeruk merupakan obat untuk scurvy P L Panum Studi epidemiologi klasik tentang penyakit campak di pulau Faroe (1875)

Sejarah perkembangan epidemiologi John Snow (1813 – 1858) Ahli anestesi Melakukan serial investigasi kolera di London Bapak Epidemiologi Lapangan Melakukan studi epidemik kolera (1854)

Snow’s Methods Ecological studies Cohort Case-control compared cholera rates by region Cohort compared cholera rates in exposed and non-exposed individuals Case-control compared water source in cases and controls

Snow’s Ecological Analysis Southwark Water Company neighborhoods  high rates Mixed service  intermediate rates Lambeth Water Co. neighborhoods  no cases Gerstman Chapter 1

Snow first used vital statistic from the registrar general that compared mortality by source of water by subdistricts. In the subdistricts in which supply was from Lambeth only, there was no death while in the subdistrict while the supply was mostly by Sothwark&Vauxhall, the death rate was very high. Gaining permission from the Registrar General, Snow was supplied with addresses of persons who died from Cholera. He went into the subdistrict of Kensington One and Two and found that 38 out of 44 deaths in this subdistrict received their water from Southwark and Vauxhall Company.

The Grand Experiment – A retrospective study

A report to the parliament based on the continuation of the work of Snow. Dr. Snow finally able to prove his hypothesis, that is, the circumstances of the cholera poison passing down into the river, being drawn from the river and distributed through miles of pipes into people’s homes produces a specific disease throughout the community.

Snow’s Cohort Study (Table 1.7, p. 25) Cholera mortality per 10,000 household and water source Rate Southwark & Vauxhall = 1263 / 40,046 × 10,000 = 315 Rate Lambeth = 98 / 26107 × 10,000 = 37.5 Southwark & Vauxhall drew water from fecal contaminated water region Supporting evidence for water-borne transmission theory

Snow’s Cohort Analyses Water Source Cases Homes Rate per 10,000 Southwark 1263 40,046 315* Lambeth 98 26,107 37 Both 1422 256,423 59 * Rate, Southwark = 1263 / 40,046 = .0315 = 315 / 10,000

Snow’s Case-Control Study Epidemic area of Golden Square area (1854 epidemic) Interviewed cases and non-cases to determine water source Cases 61 used water from Broad St. pump 6 did not use Broad St. pump 6 could not determine if used Broad St. pump Controls were less likely to use Broad St. pump water e.g., Among Brewer workers (non-cases), “the men were allowed a certain quantity of malt liquor, and Mr. Huggins [the proprietor] believes they do not drink water at all” Map showing proximity to pump and no. of cases (next slide)

Cholera Deaths – Broad St. Outbreak

Snow’s Map (Fig 1.14)

Visualization Success Stories Illustration of John Snow’s deduction that a cholera epidemic was caused by a bad water pump, circa 1854. Horizontal lines indicate location of deaths. From Visual Explanations by Edward Tufte, Graphics Press, 1997

John Snow: A Classic Epidemiologic Study The Father of field epidemiology investigating the outbreak of cholera in Gloden Square of London descriptive epidemology --> hypothesis generation --> hypothesis testing ---> public health application

Golden Square Cholera Outbreak: John Snow (2) Theory Hypothesis Hypothesis test Public Health Application Action Water was the source of disease Correlation of the distribution of cholera case households and the location of water pumps Removed the handle of the pump in Broad Street

London Cholera Outbreak: John Snow (3) Theory Hypothesis Hypothesis test Public Health Application Action Water served as vehicle for transmitting choler based on time, place, and person; compared groups are comparable changing the location of water intake to avoid water contamination

Sejarah perkembangan epidemiologi Studi epidemiologi klasik awal James Lind Melakukan studi epidemiologi ekperimen pada etiologi dan pengobatan scurvy (1753) Makan jeruk merupakan obat untuk scurvy

Sejarah perkembangan epidemiologi

Sejarah perkembangan epidemiologi

Sejarah perkembangan epidemiologi

Sejarah perkembangan epidemiologi Goldberger (1923) Menggunakan studi epidemiologi observasional dan eksperimen tentang pellagra (defisiensi asam nikotinat)

Joseph Goldberger (1874-1929) used observational and experimental epidemiologic methods to identify vitamin deficiency as the cause of pellagra; identified diets high in cereals and canned food as a risk factor; proved sources of fresh animal protein and legums were effective in prevention; first nutritional epidemiologist.

Sejarah perkembangan epidemiologi Hill, Doll, Wynder, Cornfield and other Post world war II epidemiologists. World War II is a convenient watershed to mark the risk of the "modern epidemiologists", since this coincides with the emergence of chronic disease as major causes of morbidity and mortality; focuses on individual risk factors; hallmarked by studies on : smoking and lung cancer, The Surgeon General's Report on Smoking and Health, the Framingham heart studies, water fluoridation trials, and the poliomyelitis field trials of 1954.

Maturation of Epidemiology (1910 - 1945) Key methodologic developments include the advancement of epidemiologic theory, outbreak investigation methods, methods to study non-infectious diseases (case-control and cohort methods), the introduction of randomized clinical trials, and new survey methods developed by Goldberger in the study of pellagra). Also, changes in the education of physicians and health care took place in the 1910s and 1920s, respectively

Last half of 20th Century ("Modern Epidemiology") The epidemiologic transition from acute contagious to chronic non-contagious causes of morbidity effected the way epidemiologists studied disease Illustrative examples British Doctors Study (Doll & Hills studies of the effects of smoking) Framingham Heart Study (risk factors for heart disease, many investigators)

Sejarah perkembangan epidemiologi Doll dan Hill (1950) Studi Merokok dan kaitannya dengan kanker paru dan studi penyakit kardiovaskular pada penduduk Framingham, Massachusetts (Dawber, Kannel, dan Lyell, 1963. Gordon, Castelli, Hjortland, Kannel, dan Dawber, 1977) Riset epidemiologi pada penyakit kronik (Freedman, Chear, Srinivasan, Webber, dan Berenson, 1985) Bogalusa Heart Study (Stamler, Wentworth, dan Neaton, 1986) Multiple Risk Factor Intervention Trial

Doll and Hill, 1952 Lung cancer cases Controls OR Smoke 25+ per day 331 (24%) 166 (12%) 17.4 Smoke 5-24 per day 1019 (75%) 1130 (83%) 7.8 Non-smoker 7 (1%) 61 (5%) 1

Estimated 10-Year CHD Risk in 55-Year-Old Adults According to Levels of Various Risk Factors Framingham Heart Study A B C D Blood Pressure (mm Hg) 120/80 140/90 140/90 140/90 Total Cholesterol (mg/dL) 200 240 240 240 HDL Cholesterol (mg/dL) 50 50 40 40 Diabetes No No Yes Yes Cigarettes No No No Yes mm Hg = millimeters of mercury mg/dL = milligrams per deciliter of blood Source: Circulation 1998;97:1837-1847.

Estimated 10-Year Stroke Risk in 55-Year-Old Adults According to Levels of Various Risk Factors Framingham Heart Study A B C D E F Systolic BP* 95-105 130-148 130-148 130-148 130-148 130-148 Diabetes No No Yes Yes Yes Yes Cigarettes No No No Yes Yes Yes Prior Atrial Fib. No No No No Yes Yes Prior CVD No No No No No Yes *BP in millimeters of mercury (mmHg) Source: Stroke 1991;22:312-318.

A B C D E F Systolic BP* 95-105 130-148 130-148 130-148 130-148 130-148 Diabetes No No Yes Yes Yes Yes Cigarettes No No No Yes Yes Yes Prior Atrial Fib. No No No No Yes Yes Prior CVD No No No No No Yes *BP in millimeters of mercury (mmHg) Estimated 10-year stroke risk in 55-year-old adults according to levels of various risk factors (FHS). Source: Wolf et al., Stroke.1991;22:312-318.

Offspring CVD Risk by Parental CVD Status: Framingham Study Parental CVD <55 men, <65 Women Risk Ratio 2.5 2 2.2 1.5 1.7 1.7 1.7 1 1.0 1.0 0.5 Men Women Adjusted for: age, total/HDL Chol. ratio, SBP, smoking, diabetes, BMI

Aplikasi Epidemiologi

Kontribusi epidemiologi (1) Penyelidikan modus transmisi penyakit baru Penentuan sebab-sebab penyakit yang dapat dicegah Penentuan riwayat alamiah penyakit Pengamatan spektrum penyakit

Kontribusi epidemiologi (2) Penilaian intervensi kesehatan komunitas Penyusunan prioritas pemberantasan penyakit Perbaikan diagnosis, pengobatan dan prognosis penyakit klinis Peningkatan riset pelayanan kesehatan Penyediaan saksi ahli dalam pengadilan

History of Epidemiology HIPPOCRATES (400 BC): “On Airs, Waters, and Places” –Hypothesized that disease might be associated with the physical environment, including seasonal variation in illness. JOHN GRAUNT (1662): “Nature and Political Observations Made Upon the Bills of Mortality” – First to employ quantitative methods in describing population vital statistics. JOHN SNOW (1850): Formulated natural epidemiological experiment to test the hypothesis that cholera was transmitted by contaminated water.

History of Epidemiology (cont.) DOLL & HILL (1950): Used a case-control design to describe and test the association between smoking and lung cancer. FRANCES at al. (1950): Huge formal field trial of the Poliomyelitis vaccine in school children. DAWBER et al. (1955): Used the cohort design to study risk factors for cardiovascular disease in the Framingham Heart Study.

Brief History of Epidemiology Classical Infectious Diseases Epidemiology Edward Jenner (1749-1823) developed a vaccine against smallpox using cow pox 160 years before virus was identified John Snow (1813-1858) described the association between dirty water and cholera 44 years before vibrio was identified Ignaz Semmelweis (1818-1865) described the association between childbed fever and physician’s unclean hands 32 years before causal agent was discovered For a brief history of epidemiology: Edward Jenner (1749 to 1823) - observed that persons who had been infected with cow pox - were not likely to get small pox. He used a vaccine from cow-pox effluence to inoculate against small pox - and it worked. Spring, 1999 Jan Risser, PhD Will Risser, MD PhD

Brief History of Epidemiology Classical Nutritional Epidemiology James Lind (1716-1794) conducted an experiment which showed that scurvy could be treated and prevented with limes, lemons, and oranges ascorbic acid was discovered 175 years later Joseph Goldberger (1874-1927) identified that pellagra was not infectious but nutritional in origin and could be prevented by increasing the amount of animal products in the diet and substituting oatmeal for corn grits niacin was discovered 10 years later Spring, 1999 Jan Risser, PhD Will Risser, MD PhD

Brief History of Epidemiology Epidemiology of Chronic Diseases Observational Studies: R Doll & AB Hill. Early case-control study. Smoking and carcinoma of the lung: Preliminary report. [Br. Med. J. 2:739, 1950] Cohort Studies: An approach to longitudinal studies in a community: the Framingham study. 10,000 residents gave baseline information. Follow-up is now 50 years. [Annals New York Academy of Sciences 107:539;1963] Spring, 1999 Jan Risser, PhD Will Risser, MD PhD

Brief History of Epidemiology Epidemiology of Chronic Diseases Experimental Studies: Hypertension Detection and Follow-up Program Cooperative Group. 10,500 subjects randomly assigned to two groups: 1. stepped care - antihypertensive therapy increased stepwise to achieve and maintain blood pressure reduction to goal. 2. Referred care - subjects were referred to their primary care physician and treated as usual. mortality stepped care 9.0/100 referred care 9.7/100 final blood pressure 84.1 in stepped care 89.1 in referred care Spring, 1999 Jan Risser, PhD Will Risser, MD PhD

Brief History of Epidemiology Epidemiology of Chronic Diseases Physician Health Study randomized, placebo-controlled, double-blind clinical trial conducted entirely through the mail 22,071 male physicians enrolled to study the effects of aspirin on cardiovascular disease and the effects of beta-carotene on cancer randomly assigned to one of four groups aspirin beta carotene active active active placebo placebo active placebo placebo Spring, 1999 Jan Risser, PhD Will Risser, MD PhD

ROOTS OF MODERN EPIDEMIOLOGY 1. ACUTE DISEASE INVESTIGATION ----- Emphasis on empirical systematic investigation, biology, and environment/host manipulation 2. MEDICINE ----- All early epidemiologists were physicians.

ROOTS OF MODERN EPIDEMIOLOGY 3. STATISTICS ----- Emphasis on the scientific method, quantification and measurement, and hypothesis testing. In 1960s, many epidemiologists were statisticians. 4. SOCIAL SCIENCES ----- Investigation of human behavior in relation to disease, and methods of data collection (surveys, etc.)

ROOTS OF MODERN EPIDEMIOLOGY 5. COMPUTER SCIENCES ----- Emergence of “chronic” disease epidemiology required the ability to handle large amounts of data and to perform complex analyses. 6. MANAGERIAL SCIENCES ----- Management principles for acquisition of grants, research collaboration, and management of clinical trials.

ROOTS OF MODERN EPIDEMIOLOGY 7. GENOMICS ----- 2001 marked first publication of draft sequences of the human genome. Intensive investigations being conducted to identify “disease susceptibility genes” “gene- environment” interactions, and “gene-gene” interactions.

Classical versus Modern Applications Classical: descriptive, observational, field, analytical, experimental, applied, healthcare, primary care, hospital, CD, NCD, environmental, occupational, psycho-social, etc Modern: risk-factor, molecular, genetic, life-course, CVD, nutritional, cancer, disaster, etc