A screening tool for narcissistic personality disorder (NPD) in older adults is lacking.

The study aimed to develop a screening tool for detecting symptoms of the NPD and to validate its psychometric properties in older adults.

This Narcissistic Personality Screening Questionnaire (NPSQ) was developed by constructing items based on DSM-5 criteria of the narcissistic personality disorder (NPD). A literature review regarding the signs and symptoms of NPD was conducted. Interview with NPD patients, the patients’ key informants, and a focus group discussion among psychiatrists, psychiatric nurses and psychiatry residents who have experience in working with patients with NPD were performed. After the items were created, the content validity index (CVI) by 1 psychologist and 1 psychiatrist was analyzed. A field trial was conducted among older adult patients visiting the psychiatry and the cardiology departments at Maharaj Nakorn Chiang Mai hospital between March and April 2021. The internal consistency using Cronbach alpha was analyzed.

Item hierarchy, item difficulty, and item fit was also calculated using

Rasch analysis. Qualitative information was analyzed regarding language use and time to complete the test.

Originally, a total of 80 NPSQ items with 4-Likert scales i.e., strongly agree, moderately agree, slightly agree, and disagree were generated. The CVI was 0.75-1 for item-CVI and 0.89 for scale-CVI. The NPSQ was examined among 30 Thai older adults with a mean age of 70.76 ± 6.23 years. The percent of missing items of all 80 items ranged from 2.9% to 8.9%. Cronbach’s alpha for the 80-item NPSQ was

To determine the correlation of hippocampal volume with Mini-Mental State Examination 0.96. Rasch analysis identified 37 misfitting with a mean square > 1.50, therefore 43 items remained. Person-item map showed a good target between items and sample, even though some items may be redundant. Cronbach’s alpha for the 43-item NPSQ was 0.96. Some participants were confused about who the questions referred to, which were then revised before including it in the final draft version. Only one participant did not complete the questionnaire.

The 43 item NPSQ shows good content validity and an excellent internal consistency among older adults. A study with a larger sample size is warranted.