CH3 Epidemiology and Toxicology

Question 1

difference between analytical and descriptive epidemiology

Answer 1

descriptive- who what where when; makes comparisons and develops hypotheses based on observed distributions
analytical- tests hypotheses from descriptive studies(and then makes comparisons)

Question 2

what is clustering

Answer 2

closely grouped series of events or cases of a disease (spatial- geographic or temporal- time intervals)
usually extremely unusual event

Question 3

why we use occupational epidemiology studies to apply to general population

Answer 3

exposure to hazards occurs at higher frequency in workers, also most of population is employed

Question 4

difference between counts and ratios and proportions

Answer 4

counts= number of disease cases
ratios= fraction
proportions= a ratio in which numerator is part of denominator (prevalence)

Question 5

what is prevelance (also point and period prevalence)

Answer 5

# of people affected/ # in population
point= proportion of cases at a point in time
period= proportion during time period (week, month,etc)

Question 6

define incidence

Answer 6

number of instances during a period of time (# of new cases/ total population at risk)

Question 7

limitations of crude rates for comparing populations

Answer 7

can be affected by systemic factors (age, demographic, etc.), may not reflect true variations in rates.
use specific rates instead

Question 8

when do we use the indirect method of rate adjustment

Answer 8

when standard population and age-specific rates are not readily available (often used for occupational studies)

Question 9

3 compontents of eidemiological triangle

Answer 9

agent, environment, host

Question 10

occupational health data sources

Answer 10

surveillance data, surveys, exposure measurements, employment records, statistics data

Question 11

gold standard for evidence-based practice

Answer 11

clinical trials

Question 12

what are cross-sectional studies

Answer 12

investigate relationship between diseases and other variables of interest in a population at one time

Question 13

what are ecological studies

Answer 13

units of analysis are populations or groups, rather than individuals (ex different occupational groups)

Question 14

what is a case-control study

Answer 14

participants based on presence or absence of outcome or disease of interest (case and control groups)
evaluate many diff exposures but few outcomes
retrospective

Question 15

what an odds ratio measures

Answer 15

association between exposure and outcome in case-control study

Question 16

what is a cohort study

Answer 16

subjects classified w exposure and observes them overtime to document new disease cases
evaluates many diff outcomes, few exposures

Question 17

what is relative risk (cohort study)

Answer 17

measure of association, ratio of disease incident rates in exposed to incident rates of nonexposed

Question 18

what is an experimental study

Answer 18

factor is manipulated (such as an exposure)

Question 19

what is a confounding variable

Answer 19

other factors that may influence occurence of the outcome (ex: silica exposed workers may have higher smoking rates)

Question 20

what is the threshold of the dose-response curvre

Answer 20

lowest dose at which a particular response may occur

Question 21

john snow’s epidemiologic study in london looked at

Answer 21

cholera outbreak in soho district, mapped well locations, is now regarded as father of epidemiology

Question 22

Which of the following observational designs is used for hypothesis testing?

Answer 22

cross sectional or ecologic

Question 23

list all 3 workplace exposure limit abbreviations

Answer 23

OEL (occupational expsoure limit)
TLV (threshhold limit value)
BEIs (biological exposure indices

Question 24

what is a pandemic

Answer 24

Occurrence of illness worldwide or crossing international bounds of large numbers

Question 25

what is an epidemic

Answer 25

Occurrence of illness regularly found among particular people or in a certain area

Question 26

define risk

Answer 26

probability of experiencing an adverse effect

Question 27

The study of the effects of work place exposures on the frequency and distribution of diseases and injuries in the population is

Answer 27

occupational epidemiology

Question 28

what is an endemic

Answer 28

illness habitually present in a geographic area