Module 8 Flashcards

Question

Z test for difference in proportion

Answer 1

Compare proportion with attribute from two populations Need to know: -Proportion with attribute in each population -Size of each population

Answer 2

1. Experimental studies 2. Observational studies – Descriptive studies: cross-sectional surveys – Analytic studies: many ecologic studies, case-control studies, cohort studies

Answer 3

– Used to identify a health problem that may exist – Characterize the amount and distribution of disease

Answer 4

– Follow descriptive studies | – Used to identify the cause of the health problem

Answer 5

``` #1 Experimental study #2 Prospective cohort study #3 Retrospective cohort study #4 Nested case-control study ```

Answer 6

Correlations are obtained between exposure rates and disease rates among different groups or populations *Unit of analysis is the group, not individual

Answer 7

Observations made at the group level may not represent the exposure-disease relationship at the individual level *Occurs when incorrect inferences about the individual are made from group level data

Answer 8

– Quick, simple, inexpensive | – Good approach for generating hypotheses when a disease is of unknown etiology

Answer 9

– Ecological fallacy | – Imprecise measurement of exposure and disease

Answer 10

o Survey done at particular point in time o Exp and dis measures obtained at individual level o Exp and dis outcome determined simultaneously o Cases of disease are prevalent (not incident) o Single period of observation o Both probability and non-probability sampling used

Answer 11

– Hypothesis generation – Intervention planning – Estimation of the magnitude and distribution of a health problem

Answer 12

– Do not provide incidence data – Cannot study low prevalence diseases – Cannot determine temporality of exposure & disease

Answer 13

- Compare persons with disease (cases) with those without disease (controls) - Explore whether differences between cases and controls result from exposures to risk factors. * Useful when population is not well-defined

Answer 14

- When disease is identified—PRESENT - When exposure/treatment is recognized—PAST - When analysis is conducted—PRESENT

Answer 15

- Exposure data are difficult/expensive to obtain o Disease is rare - Disease has long induction/latent period - Little is known about disease - Underlying population is dynamic

Answer 16

– Tend to use smaller sample sizes than surveys or prospective studies. – Quick and easy to complete. – Cost effective. – Useful for studies of rare diseases

Answer 17

– Provide indirect estimate of risk – Timing of exposure-disease relationship difficult to determine – Representativeness of cases/controls often unknown

Answer 18

``` o Cases usually have the disease o Define cases specifically o Signs/symptoms o Clinical exams o Diagnostic tests ```

Answer 19

o Clinic patient rosters o Death certificates o Surveys o Cancer/birth defect registries

Answer 20

o Population controls o Hospital/clinic controls o Illnesses must be unrelated to exposure o Illnesses must have same referral pattern to HCF o Dead controls—some cases deceased o Friend/spouse/relative controls

Answer 21

o In-person/telephone interview o Questionnaires o Existing datasets: medical records, pharmacy databases, registry, employment/insurance/birth/death records o Biological specimens—biomarkers

Answer 22

o Frequency disease population is small o Cases/controls are representative o Can’t calculate relative risk (RR) directly

Answer 23

RR = # times more likely cases are to get disease than controls given exposure

Answer 24

``` An estimate of relative risk o When cases/controls are representative o If disease prevalence is small OR = 1 implies no association o If > 1.0, then increased risk o If ```

Answer 25

– Controls are representative of a target population – Cases are representative of all cases – The frequency of disease in the population is small

Module 8 Flashcards

(49 cards)