Epidemiology Flashcards
(52 cards)
Which of the following is not an advantage of the prospective cohort study?
It usually cost less than a case control study
What is epidemiology?
Epidemiology is the study of the distribution and determinants of disease in human populations.
Retrospective cohort studies are characterized by all of the following except?
The required sample size is smaller than that I needed for a Prospective of cohort study
A major problem resulting from the lack of randomize in a cohort study is
The possibility that a factor that led to the exposure, rather then the exposure itself, might have caused the disease.
In a study of a disease in which all cases that developed where ascertained, if the relative risk for the association between a factor and the disease is equal to or less than 1.0, then:
There is no association or a negative association between the factor and the disease
Controls are needed in case control study because
They provide a comparable estimate of the frequency of exposure in the absence of disease
The strength of an association between a factor and a disease is best measured by
Relative risk
All of the following are important criteria when making casual inferences except
Predictive value
Which of the following is an approach to handling confounding
Individual matching, stratification, group matching, and Adjustment
Which of the following is an advantage of the case control study
It may be used to study etiology of a rare disease
In 1945, there were 1000 women who worked in a factory painting radio dials on watches. The incidence of bone cancer in these women up to 1975 work compared with that of 1000 women who worked as telephone operators in 1945. 20 of the radio dial painters and four of the telephone operators developed bone cancer between 1945 and 1975 this study is an example of a
Cohort study
Residents of three villages with three different types of water supply were asked to participate in a survey to identify cholera carriers. Because several cholera had occurred in the recent past, virtually everyone present at the time submitted to examination. The proportion of the residents in each village were carriers was computed and compared. Classify this study?
Cross-sectional study
In a case control study, which of the following is true
The proportion of cases with the exposure is compared with the proportion of controls with the exposure. The investigator may choose to have many comparison groups. Recall bias is a potential problem.
Several studies have found that approximately 85% of cases of lung cancer are due to cigarette smoking. This measure is an example of?
Attributed risk
Factor A, B, or C can each individually cause a certain disease without the other two factors, but only when followed by exposure of factor X. Exposure to factor X alone is not followed by the disease, but the disease never occurs without the absence of exposure to factor X. Factor x is
A necessary but not sufficient cause
Factor A, B, or C can each individually cause a certain disease without the other two factors, but only when followed by the exposure to factor X. Exposure to factor X alone is not followed by the disease, but the disease never occurs in the absence of exposure X. Factor A is?
Neither necessary or sufficient
What does group matching mean in the case control study
Group matching allows for both cases and controls to be comparable to all possible factors. An example can be that 25% of cases are married then 25% of controls must also be married
What does the confounding factor mean in an epidemiological study?
Confounding factor is a factor that is accompanied by a known factor that causes a disease.
What does bias mean and what are the major biases and and epidemiological study?
Information bias, selection bias, and confounding. To favor or to conclude without actual evidence.
When is odds ratio a good estimate of relative risk
- When the cases studied are representative, with regard to history of exposure, of all people with the disease in the population from which the cases were drawn.
- When the controls studied are representative, with regard to history of exposure, of all people without the disease in the population from which the cases were drawn.
- When the disease being studied does not occur frequently
What made John Snow’s work on Cholera noteworthy?
He was one of the first person to use methods based on population-based patterns of disease and take effective action in the prevention of future disease.
Epidemic means that a disease is or has
Has an excess of normal expectancy than previous years
Which of the following is a characteristic of single exposure, common vehicle outbreak?
Explosive
After infection with HIV, the virus multiplies and progressively destroys immunocompetent Cells. Early in this phase, there are few signs or symptoms in the host. This period of disease is called
Incubation period
