Final answer:
The number of false-negative results cannot be determined without additional specific data, such as the number of true cases. However, a 20 percent Type II error rate implies that 20 percent of the true cases would result in false negatives. Hospitals manage indeterminate test results by further testing to confirm the diagnosis.
Step-by-step explanation:
Based on the data provided, it is not possible to directly answer the question about the number of false-negative results without additional information. The question requires specific results from a test which are not provided. However, it is mentioned that the screening test has a 20 percent probability of a Type II error, which typically indicates a false-negative result. A Type II error in a clinical efficacy test is when the test fails to detect a condition (like TB) when it is actually present.
Since the question mentioned a 20 percent Type II error rate, if one knows the number of true cases (people who actually have the condition), one can calculate the expected false negatives by taking 20 percent of that number. For example, if there were 100 people who actually had TB, one would expect 20 people to have a false-negative result based on this error rate. Without the number of true cases, a step by step explanation to determine the false negatives is not feasible.
Hospitals usually address indeterminant western blot results with additional testing to confirm the presence or absence of the condition being tested for. In some cases, this might include repeating the test or using a different type of test to ensure an accurate diagnosis.