Test quoted as highly sensitive means -
Ans. is B High true positive and low false negativeSensitivity= true positives/(true positive + false negative) o When a screening test is used to diagnose a disease, the test outcome can be positive (diseased) or negative (healthy), while the actual health status of the person may be different, o In that setting i) True positive - Diseased people correctly diagnosed as diseased. ii) False positive - Healthy people wrongly identified as diseased. iii) True negative - Healthy people correctly identified as healthy. iv) False negative - Diseased people wrongly identified as healthy. o There are two major statistical measures for the validity of a screening test: - Sensitivity Specificity Sensitivity o It is the ability of a test to identify correctly all those who have the disease, i.e., true positive. o In other words, sensitivity measures the percentage of sick people who are identified as having the disease, o For example if a test is 90% sensitive, that means out of 100 diseased people, it will diagnose 90 (90% of diseased people will be diagnosed). Remaining 10% will be wrongly identified as not having the disease, i.e., false negative. Specificity o It is the ability of a test to identify correctly those who do not have the disease i.e., true negative o In other words, specificity measures the percentage of well people who are identified as not having the disease. o For example, a 90 percent specificity means that 90% of non diseased people will be identified as not having the disease. The remaining 10% will be wrongly classified as diseased, i.e., false positive. True positive is directly related to sensitivity False negative is inversely related to sensitivity True negative is directly related to specificity False positive is inversely related to specificity
High false positive and low false negative
High true positive and low false negative
High true positive and low false positive
Low false positive and high false negative