Question

Explain why clinicians may be overly influenced by negative tests with poor sensitivity. (consider the implications of diagnostic tests that demonstrate poor sensitivity)

Answer 1

Validity of diagnostic test is evaluated in terms of its ability to accurately assess the presence and absence of the target condition. When a test has high sensitivity,it will properly identify most of those who have the disorder.if the test is good at finding those who have the disorder ,then we could be sure that someone with a negative test will not have the disorder.Because if they did have the disorder,the test will correctly identify as having the condition ie positive test.With a more sensitive test ,positive cases are identified and therefore it is less likely that an individual with a negative test wi1ll have the disease.This results in a highly negative predictive value.For Eg in an autoimmune disorder with not a single test to diagnose ,a blood test is used ie ANA for lupus,which is very sensitive.if the patient is having lupus ANA is not specific as people who dont have Lupus can get tested positive for ANA.10% of normal people will have positive ANA ,others like people with RA will also test positive.