Community Medicine (PSM) · Biostatistics (Measures of Central Tendency, Tests of Significance, Sampling)

A likelihood ratio positive (LR+) of 10 for a diagnostic test means:

  • A The test has a sensitivity of 10% for the disease
  • B 10% of positive tests are false positives
  • C A positive result is 10 times more likely to come from a diseased person than a non-diseased person
  • D The post-test probability is 10 times the pre-test probability
Correct answer: C. A positive result is 10 times more likely to come from a diseased person than a non-diseased person

Explanation

LR+ = Sensitivity / (1 − Specificity). It represents the odds of a positive test result in a diseased individual relative to a non-diseased individual. LR+ >10 is considered strong evidence; it multiplies pre-test odds by LR+ (via Fagan nomogram) to yield post-test odds — it does not directly multiply probabilities.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.

Sponsored

Want to test yourself?

Create a free account for timed mock tests, mistake tracking, and FSRS spaced-repetition revision across 23,000+ MCQs.

Start free → Log in

More Biostatistics (Measures of Central Tendency, Tests of Significance, Sampling) MCQs

See all Biostatistics (Measures of Central Tendency, Tests of Significance, Sampling) MCQs →