Psychometric properties and score distributions of the Clinical Outcomes in Routine Evaluation measures within a non-help-seeking population from Spain

Abstract

Background: The Clinical Outcomes in Routine Evaluation (CORE) system is widely used to assess psychological well-being and clinical symptoms across various settings, but most studies on its psychometric properties have focused on clinical populations and the 34-item version, leaving a gap in understanding the performance of shorter versions and its applicability in non-help-seeking samples. Objective: This study investigates the acceptability, reliability, and score distributions of various forms within the CORE system among a non-help-seeking Spanish population. Methods: Data from 1667 participants were analyzed, with a mean age of 37.16 years and a predominance of women (59.1%). The majority had higher education (53.1%), and over half were employed at the time of the study. Results: Acceptability was high, with low item omission rates (<0.1%) across all forms during both initial and retest assessments. Internal consistency was strong, with Cronbach's alpha and McDonald's Omega exceeding 0.80 for all forms. Test-retest reliability showed correlations above 0.59 for all scores, with no significant differences between assessment intervals. Score distributions were compared by gender, age, and education, revealing significant differences between gender and education but not for age. Conclusion: The study provides key reference data for the CORE system in Spain, supporting outcome comparisons in non-help-seeking samples. Despite an overrepresentation of highly educated individuals, it offers crucial insights into its psychometric properties and score distributions. The findings highlight potential applications of these distributions and underscore the need for further research into the psychometric performance of individual CORE forms.