A 36-year-old female presents to clinic inquiring about the meaning of a previous negative test result from a new HIV screening test. The efficacy of this new screening test for HIV has been assessed by comparison against existing gold standard detection of HIV RNA via PCR. The study includes 1000 patients, with 850 HIV-negative patients (by PCR) receiving a negative test result, 30 HIV-negative patients receiving a positive test result, 100 HIV positive patients receiving a positive test result, and 20 HIV positive patients receiving a negative test result. Which of the following is most likely to increase the negative predictive value for this test?
ADecreased prevalence of HIV in the tested population
BIncreased prevalence of HIV in the tested population
CIncreased number of false positive test results
DIncreased number of false negative test results
EDecreased number of false positive test results
A mother presents to the family physician with her 16-year-old son. She explains, "There's something wrong with him doc. His grades are getting worse, he's cutting class, he's gaining weight, and his eyes are often bloodshot." Upon interviewing the patient apart from his mother, he seems withdrawn and angry at times when probed about his social history. The patient denies abuse and sexual history. What initial test should be sent to rule out the most likely culprit of this patient's behavior?
AComplete blood count
BSexually transmitted infection (STI) testing
CBlood culture
DUrine toxicology screen
ESlit lamp examination
A home drug screening test kit is currently being developed. The cut-off level is initially set at 4 mg/uL, which is associated with a sensitivity of 92% and a specificity of 97%. How might the sensitivity and specificity of the test change if the cut-off level is changed to 2 mg/uL?
ASensitivity = 92%, specificity = 97%
BSensitivity = 95%, specificity = 98%
CSensitivity = 100%, specificity = 97%
DSensitivity = 90%, specificity = 99%
ESensitivity = 97%, specificity = 96%
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