Odds Ratio Research Paper
APPLIED EPIDEMIOLOGY
1. Discuss odds ratio.
An odds ratio (OR) is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions).
In statistics, imagine each individual in a population either does or does not have a property ″A,″ and also either does or does not have a property ″B.″ For example, ″A″ might be "has high blood pressure,″ and ″B″ might be ″drinks more than one alcoholic drink a …show more content…
An odds ratio estimates the probability of disease given exposure to a specific factor by measuring the probability of exposure given the presence of disease.
Example: At a recent UM football game, a terrorist group flew a crop duster over the stadium and dusted the western side of the stands with anthrax spores. Fortunately, the wind was blowing toward the west. Once cases were discovered, the investigation began.
A total of 100 people who sat on the eastern side developed disease and 1000 people who sat on the western side developed disease. Of the 100,000 people in attendance, 50,000 were sitting on the western side of the stadium and were considered to have been exposed.
From the given data, here is the 2x2 table and odds ratio calculation.
Anthrax Yes
Anthrax No
West (Exposure Yes) …show more content…
This study type can be thought of as providing a "snapshot" of the frequency and characteristics of a disease in a population at a particular point in time. Data that are collected as part of a cross-sectional study can be used to assess the prevalence of acute or chronic conditions in a population.
Advantages to Cross-Sectional Studies
Does not require follow-up and is therefore less costly and quicker than other designs.
Are often representative of a population, rather than a smaller sub-population.
Disadvantage of Cross-Sectional Studies
Since exposure and disease status are measured at the same time it is not possible to determine the direction of the association. In other words, it is not known if the exposure preceded the disease and is therefore a potential cause of
1. Discuss odds ratio.
An odds ratio (OR) is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions).
In statistics, imagine each individual in a population either does or does not have a property ″A,″ and also either does or does not have a property ″B.″ For example, ″A″ might be "has high blood pressure,″ and ″B″ might be ″drinks more than one alcoholic drink a …show more content…
An odds ratio estimates the probability of disease given exposure to a specific factor by measuring the probability of exposure given the presence of disease.
Example: At a recent UM football game, a terrorist group flew a crop duster over the stadium and dusted the western side of the stands with anthrax spores. Fortunately, the wind was blowing toward the west. Once cases were discovered, the investigation began.
A total of 100 people who sat on the eastern side developed disease and 1000 people who sat on the western side developed disease. Of the 100,000 people in attendance, 50,000 were sitting on the western side of the stadium and were considered to have been exposed.
From the given data, here is the 2x2 table and odds ratio calculation.
Anthrax Yes
Anthrax No
West (Exposure Yes) …show more content…
This study type can be thought of as providing a "snapshot" of the frequency and characteristics of a disease in a population at a particular point in time. Data that are collected as part of a cross-sectional study can be used to assess the prevalence of acute or chronic conditions in a population.
Advantages to Cross-Sectional Studies
Does not require follow-up and is therefore less costly and quicker than other designs.
Are often representative of a population, rather than a smaller sub-population.
Disadvantage of Cross-Sectional Studies
Since exposure and disease status are measured at the same time it is not possible to determine the direction of the association. In other words, it is not known if the exposure preceded the disease and is therefore a potential cause of