Presentation of False-negative Test Results

Abstract

Sir .—Taubman et al 1 in January 1989 issue of AJDC discuss an extremely important issue—use of a rapid latex agglutination test for detection of group A β-hemolytic streptococcal pharyngitis in an office setting. Their study design demonstrates importance of comparing a new test with the gold standard (ie, a reference laboratory culture) as well as with customary test (ie, throat cultures incubated and interpreted in pediatric office). The authors introduce a term, percent of false-negative results (% FN*), that they define as follows: where TN indicates true negatives; TP, true positives; and FP, false positives. In a situation like this, risk of undetected group A β-hemolytic streptococcal pharyngitis (ie, false-negative tests) is usually communicated by negative predictive value (PV neg ) of test, an established and frequently used term in clinical epidemiology. If authors wish to refer to proportion of