Development and initial validation of the THL Adverse Childhood Experiences Questionnaire (ACE-THL)

Background: The research on adverse childhood experiences (ACEs) has deepened our understanding of the long-lasting and cumulative effects of childhood adversities. However, the instruments measuring ACEs have several shortcomings, including limited item coverage, collapsing of items and response options, simplistic scoring, and inadequate psychometric assessments. Objective: To design and conduct preliminarily psychometric testing for a brief new self-report instrument—the THL Adverse Childhood Experiences questionnaire (ACE-THL)—with a comprehensive set of clearly formulated items and appropriate response options. Methods: A previously published process model was applied to develop the ACE-THL questionnaire, which was validated by cognitive interviews (N = 20). Interviewers and interviewees completed the questionnaire separately for a cross-informant comparison. In a separate survey panel validation, the respondents filled out the ACE-THL twice, two weeks apart (N = 513, with 426 in the follow-up). Interview data were used to improve item clarity, and test–retest reliability and structural validity were assessed with repeated survey data. Results: The final 14-item questionnaire, including 12 ACE items and two items measuring protective experiences, was highly acceptable to the respondents. In the factor analysis of the quantitative data, a sufficiently single-dimensional construct was found, remaining stable in retesting two weeks later. The internal consistency (omega) of the a priori one-dimensional model was 0.89 and 0.90 at baseline and follow-up, respectively. The high test–retest reliability (mean score rank order correlation 0.93) of the ACE-THL indicated that the probed perceptions of childhood experiences are stable. Conclusion: Based on the initial validation, the 14-item ACE-THL questionnaire is a reliable and valid instrument to measure adverse childhood experiences, as well as protective experiences.