The diagnostic ability of many physical findings has been analyzed in terms of likelihood ratio

• Positive LRs of >10 and negative LRs of <0.1 generate large and often conclusive changes from pre to post test probability

• Positive LRs of 1 to 2 and negative LRs of 0.5 to 1 alter probability to a small (and rarely important) degree

So, the higher a positive likelihood ratio is, the stronger it is in predicting disease. Conversely, the smaller the negative likelihood ratio is, the better it is in predicting the absence of disease.