In a screening rest for Carcinoma Breast the sensitivity is 90% specificity is 98%, what is the chance of patient with Carcinoma breast to be detected negative in screening conducted in two consecutive years-
**Core Concept**
The question is testing the understanding of the relationship between sensitivity, specificity, and the likelihood of false-negative results in a screening test, specifically in the context of breast cancer screening.
**Why the Correct Answer is Right**
To determine the chance of a patient with carcinoma breast being detected as negative in a screening conducted in two consecutive years, we need to calculate the probability of a false-negative result in each year. Given the sensitivity of 90%, this means that 10% of patients with carcinoma breast will test negative. For each year, the probability of a false-negative result is 10% or 0.1. Since the tests are independent, the probability of a false-negative result in both years is 0.1 x 0.1 = 0.01 or 1%.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not consider the independence of the two screening tests. Even if the probability of a false-negative result in a single year is 10%, the probability of a false-negative result in both years is not 10%.
**Option B:** This option is incorrect because it does not provide a numerical value, making it unclear what it represents.
**Option C:** This option is incorrect because it is a vague statement that does not provide a clear answer to the question.
**Clinical Pearl / High-Yield Fact**
When interpreting the results of a screening test, it is essential to consider the pre-test probability of disease, as well as the test's sensitivity and specificity. In this case, the relatively high specificity of the test suggests that most true negatives will be correctly identified, but the lower sensitivity means that some cases of carcinoma breast may be missed.
**Correct Answer:** B. 1%