Psychometric Equivalence of Standard and Prorated Boston Naming Test Scores

This study compared prorated Boston Naming Test (BNT-P; omitting the noose item) and standard administration (BNT-S) scores in physical medicine and rehabilitation patients (N = 480). The sample was 34% female and 91% White with average age and education of 46 (SD = 15) and 14 (SD = 3) years, respectively. BNT-P was calculated by summing correct responses excluding item 48 and estimating the 60-item score with cross multiplication and division. BNT-P and BNT-S scores were compared via concordance correlation (CC) coefficients; reflected and log transformed data were examined with equivalence tests. BNT-P and BNT-S scores showed almost perfect agreement (CC = .99). Transformed scores demonstrated equivalence (±1.1 points). Raw and scaled score differences were 0 in 88% and 96% of cases, respectively. Race and ethnicity accounted for item 48 outcomes while controlling for age and education. Findings support the utility of prorated BNT scores in rehabilitation patients.