Epidemiology and ACS - McFarland

Question 1

Descriptive epidemiology describes what?

Answer 1

Distribution of disease
person
place
time

Question 2

Analytic epidemiology describes what?

Answer 2

Determinants of disease
risk
protection

Question 3

What topics are important in a critical review of the medical literature for a specific question or condition?

Answer 3

1. what is the question of the study
2. what is the study design
3. what is the exposure used
4. what are the outcomes and how are they measured
5. what are the inclusion and exclusion requirements
6. analysis of results
7. what are the biases and limitations of the study
8. what is the validity/generalizability of the study results

Question 4

Which types of epidemiological studies are descriptive?

Answer 4

1. Surveillance
2. case studies
3. cross-sectional
4. ecologic

Question 5

Which types of epidemiological studies are analytic?

Answer 5

1. Experimental - both clinical trials and community

2. Observational studies including cohort (both prospective and retrospective) and case-control studies

Question 6

What is prevalence?

Answer 6

of existing cases of a disease/ # in total population at a point in time

Question 7

What is cumulative incidence?

Answer 7

of new cases of a disease/ # in candidate population over a specified period of time

Question 8

What is incidence rate?

Answer 8

of new cases of a disease/ person during a time of observation in a candidate population

Question 9

Incidence and prevalence are measures of what?

Answer 9

Disease frequency.

Question 10

Absolute measures and relative measures are what?

Answer 10

Measures of comparison. Relative measures include prevalence ratio, risk ratio, rate ratio and odds ratio. Absolute measures include prevalence difference, risk difference and rate difference.

Question 11

What are the guidelines for causality?

Answer 11

1. strength of association - strong associations are more likely to be causal
2. temporality - is there evidence that exposure preceded disease
3. biological gradient/dose response - does disease risk increase as exposure level increases
4. plausibility - does the association make sense
5. consistency - do different studies using different designs yield similar results

Question 12

What is bias?

Answer 12

a systematic error that results in an incorrect or invalid estimate of the measure of association

Question 13

Internal validity asks what question?

Answer 13

Are the results free of bias?

Question 14

External validity asks what question?

Answer 14

Are the results generalizable?

Question 15

Which is more important - internal or external validity?

Answer 15

Internal.

Question 16

How do you increase external validity?

Answer 16

1. use random sampling
2. use large sample sizes
3. high response rates

Question 17

What is selection bias?

Answer 17

“is an error that results from procedures used to select subjects and from factors that influence participation in the study.”
Preferential or uneven selection of subjects
• Most likely to occur in retrospective studies because the exposure and outcome have occurred.

Question 18

What is information/observation bias?

Answer 18

Recall- occurs when there is a different level of accuracy in the information provided by compared groups (i.e. cases vs. controls, exposed cohorts vs. unexposed cohorts)

Interviewer- a systematic difference in soliciting, recording or interpreting information that occurs in studies using in person or telephone interviews.

Question 19

What is lead-time bias?

Answer 19

All cases are not detected at the same stage of the disease. (cancer)

Question 20

What is the Hawthorne effect?

Answer 20

if a subject knows that he/she is being observed or being investigated, their behavior and response can change.

Question 21

What is repeat-testing bias?

Answer 21

In a pre-test/post-test situation, the subjects tend to remember some of the previous questions and they do better regardless of the intervention. Or they may be fatigued and that alters their response.

Question 22

A confounding variable must…..?

Answer 22

1. be associated (non-causally or causally) with the exposure
2. Associated (causally) with the outcome, independent of the exposure
3. NOT be an intermediate variable in the causal pathway
   

Question 23

What are the ten leading causes of death in the US?

Answer 23

1. Heart Disease:
2. Malignant Neoplasms (Cancer)
3. Chronic Lower Respiratory Diseases
4. Stroke (Cerebrovascular diseases)
5. Unintentional Injury (Accidents)
6. Alzheimer’s Disease
7. Diabetes Mellitus
8. Influenza & Pneumonia
9. Nephritis and Nephrosis
10. Suicide (Intentional self-harm)

Question 24

Describe the prevalence of heart disease in Nevada.

Answer 24

4% of adults have been diagnosed with some form of heart disease in NV- it is the leading cause of death
There is a higher prevalence of health disease among:
• • •
black populations (7%) above the overall state average. Older adults 65+ (12%) and 55 to 64 year olds (8%)
Individuals with household incomes between $15,000 to $24,000
The prevalence of heart disease is fair equal among Clark County (4%), Washoe County (4%) and in the rural and frontier regions (5%).