ora paltiel, md, msc
DESCRIPTION
Ora Paltiel, MD, MSc Braun School of Public Health & Community Medicine Hebrew University of Jerusalem Hadassah Medical Organization Israel. Epidemiological Reasoning Using Cancer Statistics. Or, how to use descriptive statistics to raise hypotheses. Validity of data Reporting Confounding - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/1.jpg)
Ora Paltiel, MD, MSc
Braun School of Public Health & Community Medicine
Hebrew University of Jerusalem Hadassah Medical Organization
Israel
![Page 2: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/2.jpg)
Epidemiological Reasoning
Using Cancer Statistics
Or, how to use descriptive statistics to raise hypotheses
![Page 3: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/3.jpg)
Issues to be discussed
Validity of data• Reporting• Confounding • Effect
modification
Using Descriptive Data
• Burden of Disease• Planning• Hypothesis raising• Measuring
progress
![Page 4: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/4.jpg)
What are the objectives of epidemiology?
1. To determine the extent of disease (states of health) and/or behaviors in the community.
2. To identify the etiology or the cause/s of a disease and the risk factors - that is, factors that increase a person’s risk for a disease.
3. To study the natural history and prognosis of disease.
![Page 5: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/5.jpg)
4. To evaluate new preventive and therapeutic measures and new modes of health care delivery.
5. To provide the foundation for developing public policy and regulatory decisions relating to public health problems.
Objectives of epidemiology
![Page 6: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/6.jpg)
“When we measure, we know better”
- Center for Disease Control (CDC), Atlanta, Georgia,USA
![Page 7: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/7.jpg)
The epidemiological
tool-box
![Page 8: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/8.jpg)
Kaposi sarcoma in New York
0
20
40
60
80
100
73 74 75 76 77 78 79 80 81 82
Year
No
. of c
ases
![Page 9: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/9.jpg)
The context of disease reporting
![Page 10: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/10.jpg)
![Page 11: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/11.jpg)
Lowest cancer death rate
In the Former Yugoslav Republic of Macedonia, only 6
people per 100,000 of population die from cancer
each year
![Page 12: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/12.jpg)
Lifetime risk of developing breast cancer, 1940-1987
0
2
4
6
8
10
12
1940 1950 1960 1970 1980 1987
perc
ent o
f wom
en
![Page 13: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/13.jpg)
YEARONE IN.…194020195015196014197013198011
1987 9
Source: American Cancer Society, 1991
Lifetime risk of developing breast cancer, 1940-1987 cont’d
![Page 14: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/14.jpg)
Descriptive epidemiology - hypothesis raising rarely provides enough evidence for causation
Person: characteristics for study include:• Age• Gender• Religion• Marital status• Ethnicity• Occupation• Socio-economic class• Heredity vs. Environment
![Page 15: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/15.jpg)
Age-specific rates of Breast Cancer Mortality
![Page 16: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/16.jpg)
Russian Federation
Israel
Population Pyramids 1998
![Page 17: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/17.jpg)
![Page 18: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/18.jpg)
![Page 19: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/19.jpg)
Trends of Cervical Cancer Mortality in Europe and North
America
![Page 20: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/20.jpg)
Age-standardized cervical cancer death rates (and 95% confidence intervals) per
100 000 women in urban Canada by neighbourhood income quintile from 1971
to 1996. Q1 = richest Q5 = poorest .
![Page 21: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/21.jpg)
Place and time
Time trends - raise hypotheses regarding environmental factors or results of medical care
Geographic variation - on small + large scale, environmental genetic factors
Study of migrants: important for separating environmental from genetic factors
![Page 22: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/22.jpg)
Numbers of cases of cancer at 16 anatomical sites in developed and in developing countries, with relative ranks
![Page 23: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/23.jpg)
Lung Cancer Mortality for Women 1998, ASR/100000
![Page 24: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/24.jpg)
Lung Cancer Mortality for men 1998, ASR/100000
![Page 25: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/25.jpg)
Age-adjusted cancer death rates, males by site, US, 1930-1996
![Page 26: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/26.jpg)
Age-adjusted cancer death rates, females by site, US, 1930-1996
![Page 27: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/27.jpg)
![Page 28: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/28.jpg)
Estimated annual percent changes in mortality from all types of cancer in the US over 2 periods 1973-
1990 and 1991-1995, according to age group
0.7
0.3
0
-1.8
-2.1
-1.7
-1.3
-2.6
-3.4
-0.6
1.1
0.9
0.9
-0.9
-1.4
-1.1
-2.2
-3
0.4
0.4
-4 -2 0 2 4
>85
75-84
65-74
55-64
45-54
35-44
25-34
15-24
<15
All ages
Age
gro
up (y
r)
Annual change (%)
1973-19901991-1995
![Page 29: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/29.jpg)
Japanese colon cancer incidence:
Japan Hawaii California
- rate is affected by age at immigration- for breast cancer: 2 generations required for rate
Place and time cont’d
Low
IntermediateHigh
![Page 30: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/30.jpg)
Biases in migrant studies
1) Different reporting
2) Different diagnostic criteria
3) Migrants are selected group
![Page 31: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/31.jpg)
Clinical observati
on
Descriptive data
Hypothesis raising
Where does evidence come from?
![Page 32: Ora Paltiel, MD, MSc](https://reader034.vdocuments.net/reader034/viewer/2022052317/56815d9b550346895dcbc087/html5/thumbnails/32.jpg)
Clinical observati
on
Descriptive data
Hypothesis raising
Analytical studies
Hypothesis testing