2100- Suppose that 50,000 women who have never had a breast cancer diagnosis are available and willing to participate in a new screening program of...

2100- Suppose that 50,000 women who have never had a breast cancer diagnosis are available and willing to participate in a new screening program of computerized digital mammography. 1132 women had a positive screening test. All of these positive women had a breast biopsy and 136 were diagnosed with breast cancer. Of the 48,868 who screened "negative" on the test, 24 were in fact in the detectable pre-clinical phase. This was determined by following these women and observing that all 24 were diagnosed with breast cancer within one year of the screening test. What is the sensitivity of this new screening test?

12%

85%

98%

99.9%

22-Selection bias is most likely to occur in studies where

Only exposure has occurred at the time of subject selection

Only outcome has occurred at the time of subject selection

Exposure and outcome have already occurred at the time of subject selection

233-

The extent to which study data reflect the true underlying association in the target population outside the study, is referred to as:

External reliability

External validity

Internal reliability

Internal validity

244--Suppose that 50,000 women who have never had a breast cancer diagnosis are available and willing to participate in a new screening program of computerized digital mammography. 1132 women had a positive screening test. All of these positive women had a breast biopsy and 136 were diagnosed with breast cancer. Of the 48,868 who screened "negative" on the test, 24 were in fact in the detectable pre-clinical phase. This was determined by following these women and observing that all 24 were diagnosed with breast cancer within one year of the screening test. A colleague in another city reports that the same screening test (with the same sensitivity and specificity) is achieving a predictive value positive of only 6%. What is the explanation for this?

The colleague is screening a higher risk population

The colleague is screening a lower risk population

The colleague is screening a larger population

The colleague is screening a smaller population

255-Indicate the letter corresponding to the most likely stage of disease described using the key provided: A routine blood test that shows slightly elevated triglycerides in a healthy 18-year old who recently adopted poor dietary habits while at away at college

Stage of Susceptibility

Stage of Presymptomatic Disease

Stage of Clinical Disease

Stage of Diminished Capacity