Definitions For Final

Question 1

Efficacy

Answer 1

The extent to which an intervention does more good than harm under ideal circumstances

Incidence in control group - incidence in treatment group
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Incidence in control group

This gives the proportion of the outcomes that were prevented by the intervention or treatment. Example: 37.5% of cases of malaria were prevented by providing bed nets to families

Question 2

Effectiveness

Answer 2

The extent to which interventions are beneficial under “real world” conditions or in “natural” settings

Question 3

Efficiency

Answer 3

Cost benefit ratio of an effective intervention

Question 4

Screening

Answer 4

Performed in the absence of symptoms; aims to detect disease not yet under medical care; positive responders require a second, diagnostic exam

Question 5

Diagnostic test

Answer 5

Performed in the presence of symptoms; designed to diagnose the condition causing symptoms

Question 6

Mass screening

Answer 6

Application of screening tests to total population group, regardless of their risk status

Example: all health workers for TB

Question 7

Selective screening

Answer 7

Applied to high risk groups

Example: those at risk for STIs or HIV; breast cancer screening at age 40/50+

Question 8

Why randomize?

Answer 8

Ensures similarity between exposed and unexposed groups; controls for both known and unknown confounders; reduces selection and information bias

Question 9

Validity

Answer 9

The extent to which a situation as observed reflect the “true” situation