FCM - Research Design 1: Observational

Cases vs controls

What does a case control study compare?

Outcome to exposure

Direction of inquiry in a case control study.

False

T/F: Case control studies start with exposure and follow for outcome.

Odds ratio

Main measure of association in a case control study.

Rare diseases

When are case control studies most useful?

1:4

Optimum ratio of cases to controls.

Hospitals

Source where hospital-based cases come from.

Matching

What ensures comparability between cases and controls?

False

T/F: Controls must be unrelated to the source population of cases.

Interview (Medical records)

Method used to determine exposure status.

False

T/F: Different methods may be used for cases and controls.

AD/BC

Mathematical formula for odds ratio.

None

Odds ratio of 1 indicates what type of association?

Causative association

Odds ratio greater than 1 indicates what?

Preventive association

Odds ratio less than 1 indicates what?

Selection bias

Common bias when selection differs between groups.

Recall bias

Common bias when recall differs between groups.

False

T/F: Case control studies are expensive and time-consuming.

Disease patterns

What does descriptive research aim to describe?

Magnitude, distribution

Two bases for descriptive research.

False

T/F: Descriptive studies are used to test hypotheses.

Case report

Simplest form of descriptive research.

Single patient

Unit of observation in a case report.

No association testing

Main limitation of a case report.

Case series

What study collects several related case reports?

Epidemic

What can a case series help identify early?

False

T/F: Case series includes a comparison group.

Ecologic study

Study type measuring population-level associations.

Population

Unit of measurement in an ecologic study.

Ecologic fallacy

Error when applying population data to individuals.

False

T/F: Ecologic studies establish causation.

Present time

Direction of inquiry in a cross-sectional study.

Prevalence study

Other name for cross-sectional study.

False

T/F: Cross-sectional studies measure incidence.

Prevalence data

What type of data do cross-sectional studies generate?

Prevalence ratio

Measure of association in cross-sectional study.

Prevalence ratio

What formula is this: (A/A+B) ÷ (C/C+D)?

None

PR = 1 means what type of association?

Positive

PR > 1 means what association?

Protective

PR < 1 means what association?

False

T/F: Cross-sectional studies can determine causality.

Fast

Advantage of cross-sectional studies in terms of time.

Temporal ambuguity (No incidence)

One major limitation of cross-sectional studies.

Exposure status

What is a cohort study based on?

Exposure

Starting point of a cohort study.

Prospective or retrospective

Time element of a cohort study.

Relative risk

Primary measure of association in a cohort study.

Exposure to outcome

Direction of inquiry in a cohort study.

Cohort study

Study with highest level of observational evidence.

False

T/F: Cohort studies begin with diseased participants.

Select exposed

First step in conducting a cohort study.

Select unexposed

Second step in conducting a cohort study.

Internal comparison

Type of exposure group from same cohort.

External comparison

Type of comparison using a different population.

False

T/F: Unexposed group must differ in every aspect.

Relative risk

What formula is this: (A/A+B) ÷ (C/C+D)?

No association

RR = 1 means what?

Causative

RR > 1 indicates what?

Protective

RR < 1 indicates what?

Clear cause-effect

Key advantage regarding temporality.

Recall bias

Bias avoided in cohort studies compared to case control.

Attrition (Expensive)

One disadvantage regarding follow-up.

Diagnostic changes

Factor complicating long-term studies.

True

T/F: Cohort studies can examine multiple outcomes.