Abstract
OBJECTIVE: The Neuropsychiatric Inventory (NPI) is one of the most commonly used assessment scales for assessing symptoms in people with dementia and other neurological disorders. This paper analyzes its conceptual framework, measurement mode, psychometric properties, and merits and problems. METHOD: All articles discussing the psychometric properties and factor structure of the NPI were searched for in Medline via Ovid. The abstracts of these papers were read to determine their relevance to the purpose of this paper. If deemed appropriate, a full paper was then obtained and read. RESULTS: The NPI has reasonably good content validity and internal consistency, and good test-retest and interrater reliability. There is limited information about its sensitivity, specificity, positive and negative predictive values, and, in particular, responsiveness. Merits of the NPI include being comprehensive, avoiding symptom overlap, ease of use, and flexibility. It has problems in scoring (no multiples of 5, 7, and 11) and, therefore, analysis using parametric tests may not be appropriate. The use of individual subscales also warrants further investigation. CONCLUSION: In terms of its content and concurrent validity, intra- and interrater reliability, test-retest reliability, and internal consistency, the NPI can be considered as valid and reliable, and can be used across different ethnic groups. The tool is most likely unable to deliver as good a performance in terms of discriminating between different disorders. More studies are required to further evaluate its psychometric properties, particularly in the areas of factor structure and responsiveness. The clinical utility of the NPI also needs to be further explored.