hss4303b introduction to epidemiology science of the gods introduction prof r deonandan –...
TRANSCRIPT
HSS4303B
IntroductionTo Epidemiology
Science of the Gods
Introduction
Prof R Deonandan – [email protected]
Tutorial
• Currently we have a tutorial scheduled for Saturdays 10:am-11:30am in CBY C03
• However, neither I nor Tiffany have any desire to come to campus on Saturdays, so....
• Tutorials will be held for the last 30 minutes of the Monday classes, every other week
• We will keep the Saturday space for students who wish to use it as meeting space for activities related to this class
Who We Be?
• Professor– Dr Raywat Deonandan– Templeton 111 x8377– [email protected]
• Teaching Assistant– Ms Tiffany Locke– [email protected]
Please emailFor appointments
Currently, no regular office hours
Everything You Need To Know
classes.deonandan.com/hss4303
If you have a question about the class, please check the website before emailing us. I will not reply to emailed questions for which the answers are on the website or the syllabus.
The Virtual Campus website is not up yet, but will be soon. In the mean time, all class files will be kept here:
Also, I maintain an FAQ here: classes.deonandan.com/faq.html
“Not Taking it Seriously”
• In the excel spreadsheet in which I keep your marks, there’s a column called “not taking it seriously”
• This does not affect your marks, but may affect any leeway I offer you and certainly any references I write for you.
“Not Taking it Seriously”
• Asking me questions about things that are on the website...
• Asking me a question I just answered...• Not paying attention...• Not attending class and then using that as an
excuse for not knowing what’s going on...• Mistaking me for your personal assistant...• Etc.
Written Assignment
• Abstract– Very brief– Test of your reading, research, writing abilities– Test of your ability to follow instructions– Instructions are already on the website– Worth 10%– Due 11:59pm via email on Saturday Jan 29
Midterm
• Currently scheduled for Feb 28– All multiple choice!– Very similar to the one given to HSS4303A
Poster
• Your chance to play scientist!– Test your ability to collaborate, research,
summarize and present– Everyone will present on Saturday, April 9
• HSS4303A, HSS4303B and even the French section
– Instructions will be uploaded to website real soon– Worth 25%
Final Exam
• During Exam Period– Current plan is to combine HSS4303A and
HSS4303B and give both sections the same exam– This plan may change if the content diverges– All multiple choice– Sample questions will be uploaded to website– Worth 45%– Exam period: April 11-28
Textbooks?
1. Medical Epidemiology 4th Edition, by Greenberg et al and published by McGraw Hills Publications. ($56.95 + tax at Agora Books)
2. Epidemiology, by Gordis L, published by Elsevier Sauders. ($60.11 + tax at Agora Books)
The following books are required. In syllabus, readings refer to book #1.
The following book is recommended but not required:
The Rules of Raywat
1. If you don’t want to be here, don’t come-you are not marked on attendance-I’d rather you not come than to come and talk during
lectures-But you are still responsible for everything presented in class
2. Don’t piss me off-I *will* find a way to make you pay for it
Lecture Slides
• Slides are provided as a courtesy• Be sure to take your own notes because one
day there might not be any slides (I’m tricky like that)
Important Dates
• Jan 29 – written assignments are due!• Feb 20-24 – Reading Week!• Feb 28 – in-class midterm!• Mar 12 – submit your poster topic!• Apr 9 – poster presentations!• April 11 on – Exam period
Homework
• Previous years have had a mandatory tutorial for working through computational problems together
• This year, you’ll be given more take-home assignments instead (will not be marked)
• We will try to arrange 1-2 optional tutorial sessions before exams to go over the problems
What Is Epidemiology?
• “The study of the distribution and determinants of disease or health status in a population”
– CDC
• The Science of the Gods!– R. Deonandan
The Origin of Epidemiology
Dr John Snow1854Used non-medical means to discover source of cholera outbreak
Figure 1-12 Photograph of John Snow. (From the Wellcome Historical Medical Museum and Library, London.)
Figure 1-13 A drop of Thames water, as depicted by Punch in 1850. (From Extracts from Appendix (A) to the Report of the General Board of Health on the Epidemic Cholera of 1848 and 1849, published by HMSO, London, 1850. Int J Epidemiol 31:900-907, 2002.)
Shoe leather epidemiology
Epidemiology Allowed “Miasmatic Theory” to be Displaced
• Miasmatic theory– Miasma was considered to be a poisonous vapor
or mist filled with particles from decomposed matter (miasmata) that caused illnesses. It was identifiable by its foul smell.
• Supplanted by “Germ theory”– Most diseases caused by an infectious agent
HSS4303: Introduction to epidemiology
Deaths from cholera and water theory
Water supply # of houses
Deaths from
cholera
Deaths per
10,000 houses
Southwark and Vauxhall Co
40,046 1,263 315
Lambeth Co 26,107 98 38
Other districts in London
256,423 1,422 56
Types of Epidemiologists
• Clinical Epidemiologist• Public Health Epidemiologist• Population Epidemiologist
The Face of Brilliance
Some Terminology
• Clinical research or mathematical relationships:– Variable that predicts/causes an outcome is
independent variable
• Epidemiological research:– Variable that may predict/cause an outcome is
exposure
Some Terminology
• Epidemiological research:– Exposures that increase or decrease the
likelihood of developing certain disorders, conditions or diseases are called risk factors
Eg, research has shown a strong statistical association between the exposure of smoking and the outcome of having lung cancer smoking is therefore a risk factor for lung cancer.
Descriptive Studies
• A true “descriptive study” is an example of “descriptive epidemiology”– Who – What– Where– When
Descriptive Study
• Who– Students
• What– Left handedness
• Where– This class
• When– Right now
Right now, 23% of students in this class are left handed
Qualitative vs. Quantitative
Descriptive vs. Analytic
Observational vs. Experimental
Case-controlCohortCross-sectional
InterventionsClinical trials
Who gets the disease?When do they get it?Where do they get it?
What Is An Experiment?
From the internet: “the act of conducting a controlled test or investigation”
For our purposes, an experiment differs from other kinds of investigations in that the researcher manipulates something.
In 1975, two year old Rahima Banu contracted last known case of naturally-occurring variola major Smallpox. -Wikipedia
The global eradication of smallpox was certified, based on intense verification activities in countries, by a commission of eminent scientists on 9 December 1979 and subsequently endorsed by the World Health Assembly on 8 May 1980-“Resolution WHA33.3”
“You have erased from the calendar of human afflictions one of its greatest. Yours is the comfortable reflection that mankind can never forget that you have lived. Future nations will know by history only that the loathsome smallpox has existed.”
-Thomas Jefferson to Edward Jenner, 1806
– 400,000 people died each year in the late 18th century
– 1/3 of the survivors became blind– Survivors also developed immunity to smallpox– Efforts to prevent smallpox
• Variolation – Edward Jenner took interest in cowpox to find
solutions in the prevention of smallpox– WHO and eradication of smallpox
• In 1967 WHO began the eradication program• 15 million people developed smallpox annually• 2 million people died• In 1980 smallpox was “eradicated”
Before HIV was known to cause AIDS
• We knew it involved the “3 H’s”– Homosexuals– Haemophiliacs– Haitians
• Epidemiologists figured out:– It was bloodborne – It was probably a virus
Observational epidemiology
• Many a times we do not know the cause of disease but we can associate it with certain exposures– Streptococcal infection follows rheumatic fever and rheumatic heart
disease– Rheumatic fever is more frequent in army recruits than in school
children
• Lung cancer and smoking• Epidemiology based on observational data leads us to
understand the association between the morbidity and mortality from a disease and certain exposures, habits, lifestyle choices
Where Do Epidemiologists Work?
• Universities (ahem)• Government • Public health agencies• Drug companies• Hospitals (MDs)• Private companies
Breast and lung cancer mortality in Canada
20
25
30
35
1993 1994 1995 1996 1997
lung cancer breast cancer
Prevention and therapy
• Prevention is integral to public health and also to clinical practice
• In clinical practice therapy is used to prevent complications, disability and death
• Prevention in public health is primary prevention• Prevention in clinical practice is
– Secondary prevention (minimize disease complications)– Tertiary prevention (minimize disability)
• Epidemiology is the basis for effective prevention programs
Diagnostic tests: false positive and false negative tests are used to assess sensitivity and specificity
Disease surveillance• Monitoring the patterns of occurrence of a disease within a
population is referred to as _____________. • There are many potential benefits from the collection of
surveillance data:– (1) can help to identify the new outbreak of an illness, such as AIDS, – (2) can provide clues, by considering the population groups that are
most affected by the illness, to possible causes of the condition, – (3) can be used to suggest strategies to control or prevent the spread
of disease, – (4) can be used to measure the impact of disease prevention and
control efforts, and finally, – (5) can provide information on the burden of illness, data that are
necessary for determining health and medical service needs
Figure 1-14 Breast versus lung cancer mortality: white females versus black females, United States, 1973-1995, age-adjusted to 1970 standard. (From Ries LAG, Kosary CL, Hankey BF, Miller BA, Edwards BK [eds]: SEER Cancer Statistics Review, 1973-1995. Bethesda, MD, National Cancer Institute, 1998.)
Trend Analysis
Things I Want You to Think About
• Consider the following three images and the reaction they have on you. We will discuss at a later date.
• Consider: how do you respond to the numbers, do you think about who computed them and whether they are accurate, are they appropriate, and what emotional reaction do you have from them?
This is your homework
It’s put out by the Canadian Foundation for AIDS Research (CANFAR) and says, “Did you know that 86% of HIV Positive Canadians are male, And 2/3 of boys, aged 15 to 19 are sexually active? You think your kids aren’t at risk? Think again.”