Psychometric assessment of the 10-item Thai version of the Experience in Close Relationship-Revised for Adolescents (ECR-R-10-AD).

The 18-item version of the Experiences in Close Relationships-revised (ECR-R-18) is a valid and reliable scale used among Thai adolescents. However, it revealed problematic items that impacted the scale's internal consistency. The study aimed to achieve two objectives: (1) develop a new, shorter scale by retaining only highly loaded items equally between attachment anxiety and attachment avoidance, and (2) evaluate the psychometric properties of the shorter ECR-R version compared to the existing 18-item scale. Objective 1 was achieved through Study 1, involving 204 youths aged 16-18 years (64% female). All participants completed the 18-item ECR-R, and exploratory factor analysis was conducted to identify suitable items for the new ECR-R-AD. Objective 2 was fulfilled in Study 2, which included a total of 443 students in grades aged 15-18 years old (88% female) from Thai boarding schools in Northern Thailand. All participants completed both the 18-item ECR-R, and confirmatory factor analysis of both the existing 18-item and the new shorter scale was performed and compared. Additional measures including the Rosenberg Self-Esteem Scale, Perceived Stress Scale-10, and Relationship Questionnaire were completed alongside the ECR-R to assess convergent, discriminant, and criterion validity. The invariance test for the new ECR-R across genders was conducted using multigroup confirmatory factor analysis. For objective 1, Study 1 developed a new scale called "ECR-R-10-AD" with 10 items, comprising 5 for attachment anxiety and 5 for attachment avoidance. The McDonald's omega values were 0.866 for avoidance and 0.823 for anxiety subscales. The corrected correlation between the ECR-R-18 and ECR-R-10-AD was significant. For objective 2, Study 2 found that the first-order two-factor solution model fit the data best for the ECR-R-10-AD. Convergent, discriminant, and criterion validity with other measurements and invariance tests based on sex were established for the ECR-R-AD. The ECR-R-10-AD provided sufficient psychometric properties among Thai adolescents. Factorial validity, convergent validity, and measurement invariance were established. As the ECR-R-10-AD is brief, it can be administered with less burden. Limitations and future research were discussed.