Boston naming test short forms: a comparison of previous forms with new item response theory based forms

Current neuropsychological assessments often require lengthy administrations, limiting their use in clinical settings. Prior studies have shown that the Boston Naming Test (BNT) is a widely used tool for evaluating naming abilities in patients with cognitive impairments. However, the full-length BNT may be time-consuming for clinicians. No prior work had resolved how to effectively shorten the test without losing diagnostic accuracy. This gap motivated researchers to explore alternative methods for creating shorter forms of the BNT. They aimed to ensure that the shortened versions retained high reliability and diagnostic power. The study sought to address whether item response theory (IRT) could improve short-form development. The research also aimed to compare IRT-based forms with previously developed short forms. This approach could refine diagnostic efficiency in cognitive assessments.

The study aimed to develop and evaluate new short forms of the Boston Naming Test (BNT) using item response theory (IRT). Researchers focused on whether these new forms could match the diagnostic accuracy of the full-length BNT while reducing administration time. The specific problem addressed was the need for efficient yet reliable cognitive screening tools for elderly patients. The motivation came from the limitations of existing short forms, which may lack sufficient reliability or diagnostic sensitivity. The researchers proposed that IRT could better capture item difficulty and patient ability. This method could allow for adaptive testing, where fewer items are needed for some patients. The goal was to improve diagnostic efficiency without compromising accuracy. This approach could support broader use of the BNT in clinical settings.

Researchers collected data from 206 elderly outpatients to develop two new short forms of the Boston Naming Test (BNT). They applied item response theory (IRT) to select items that best represent the full test's diagnostic properties. The IRT-based short forms included 30 and 15 items, respectively. They compared these new forms with 12 previously developed short forms. A sub-sample of 69 patients with mild Alzheimer's disease (AD) or AD combined with vascular dementia (VD) was used for evaluation. The researchers assessed diagnostic accuracy by comparing abnormal classifications across forms. They calculated internal consistency using Cronbach’s alpha for each form. An adaptive version of the test was also tested, which used only 15 items for 75% of patients with normal naming ability.

The 30-item IRT-based short form of the BNT achieved a reliability of alpha = .90 and correctly identified 44% of AD/VD patients as abnormal. This form showed 93% agreement with the full BNT in classifying these patients. The 15-item IRT-based form had a reliability of alpha = .84 and identified 48% of AD/VD patients as abnormal, with 90% agreement with the full BNT. The adaptive version of the 30/15 item test matched the performance of the full 30-item test for 75% of patients with normal naming ability. The full BNT had a reliability of alpha = .90 and identified 44% of AD/VD patients as abnormal. The IRT-based forms demonstrated comparable diagnostic accuracy to the full-length test. Both new forms outperformed previously developed short forms in terms of agreement with the full test. These results suggest that IRT can effectively guide the development of shorter, reliable cognitive assessments.

The study demonstrated that item response theory (IRT) can produce short forms of the Boston Naming Test (BNT) with high diagnostic accuracy. The 30-item IRT-based form matched the full BNT in identifying abnormal naming in AD/VD patients. The 15-item form slightly improved detection rates while maintaining strong agreement with the full test. An adaptive version of the test reduced item count for 75% of patients with normal naming ability. These findings suggest that IRT-based forms may improve diagnostic efficiency without sacrificing reliability. The authors propose that these new forms could be valuable in clinical settings where time is limited. They emphasize that the IRT approach allows for better item selection based on difficulty and patient ability. The study supports the use of IRT in developing neuropsychological assessments.