External variable that impacts the effect of a risk factor (ie FHx of cancer)
Effect modifier
1 SD includes what %?
68%
2 SD includes what %
95%
3 SD include what %
99.7%
What is the null hypothesis?
That there is no relationship b/w exposure and outcome
Which values are dependent on dz prevalence in the population?
PPV and NPV
High prevalence - good PPV
Low prevalence - good NPV
The narrower the confidence interval
The more precise the result
NPV is 96%, so if a pt has a negative test what is their risk of having dz?
4%