riley measurement

What is screening?

testing for a disease in persons who are not otherwise suspected to have the disease

Sensitivity

proportion of those with disease who test positive

Sensitivity =

TP / (TP + FN)

Specificity

proportion of those without disease who test negative

Specificity =

TN / (TN + FP)

Positive Predictive Value (PPV)

proportion of positive tests that actually have disease

Positive Predictive Value (PPV) =

TP / (TP + FP)

Negative Predictive Value (NPV)

proportion of negative tests that are actually disease free

Negative Predictive Value (NPV) =

TN / (TN + FN)

When the prevalence of a disease is higher in a population, what can be expected for the proportion of false-positives?

The proportion will be lower

Validity

the legitimacy of the measurements

Reliability

the consistency of the measurements

True or False. You can have validity without reliability.

False

True or False. You can be reliable without validity.

True

Operationalization

the process of strictly defining variables into measurable factors, especially when measurement uses an ordinal scale

What are the four things you might consider when choosing how to conduct a survey?

1. Who administers the survey?
2. How much does the survey use cost?
3. Is the survey acceptable?
4. How stable is survey reliability?