Likelihood Ratio Calculator
Posted by Dinesh onOnline likelihood ratio calculator to calculate the value of performing a diagnostic test of patient's expected and target disorder in diagnostic testing.
| Likelihood Ratio | Approximate Change in Probability | Effect on Posttest Probability of disease |
|---|---|---|
| Values between 0 and 1 decrease the probability of disease | ||
| 0.1 | -45% | Large decrease |
| 0.2 | -30% | Moderate decrease |
| 0.5 | -15% | Slight decrease |
| 1 | 0% | None |
| Values greater than 1 increase the probability of disease | ||
| 1 | 0% | None |
| 2 | 15% | Slight increase |
| 5 | 30% | Moderate increase |
| 10 | 45% | Large increase |
Calculate Likelihood Ratios in Diagnostic Testing
Formula:
LR+ = (a/(a+c)) / (b/(b+d))
LR− = (c/(a+c)) / (d/(b+d))
T+ = result of the test is positive,
T− = result of the test is negative,
D+ = present disease,
D− = absent present,
LR+ = Positive likelihood ratio,
LR− = Negative likelihood ratio