Farsi version of the Neuropsychiatric Inventory: validity and reliability study among Iranian elderly with dementia

BACKGROUND: This study aimed to validate the Farsi version of Neuropsychiatric Inventory (F-NPI), with the aim of promoting clinical assessment and local research on evaluation of neuropsychiatric symptom profiles of individuals with dementia in Iran. METHODS: In this cross-sectional, psychometric study, 100 patients with dementia in the age range of 60–90 years participated. Two trained psychiatrists interviewed the study subjects. Positive and Negative Symptoms Scale (PANSS) and Geriatric Depression Scale (GDS) were used to determine the concurrent validity. Testretest,inter-rater reliability and internal consistency were calculated. Discrimination validity was determined,using a matched control group consisting of 49 participants without dementia. Cronbach’s α and Pearson’ scorrelation coefficients were used to analyze the data. RESULTS: The internal consistency (Cronbach’s α = 0.9) was excellent. The inter-rater reliability varied between 0.6 and 0.98 for frequency, severity and total scale of the F-NPI, and test-retest reliability was between 0.4 and 0.96. Concurrent validity varied between 0.3 and 0.9 (P < 0.05). The most prevalent symptom was “apathy” and the least prevalent was “euphoria”. CONCLUSION: The Farsi version of NPI has satisfactory psychometric indexes and is applicable for clinical and study works in Iranian community.