Test-Retest Reliability and Factor Structure of the Danish SCL-6 in Adolescents

Mar 18, 2025

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The following is a summary of “Test-retest reliability and factor structure of the Danish 6-item version of the Hopkins Symptom Checklist-core depression (SCL-6) in adolescents,” published in the March 2025 issue of BMC Pediatrics by Sørensen et al.

Researchers conducted a retrospective study to assess the test-retest reliability and structural and convergent validity of the Danish 6-item Hopkins Symptom Checklist-core depression (SCL-6) in adolescents.

A total of 122 adolescents participated in the study. Of these, 91 completed the SCL-6 in the first round (test sample), 82 completed it in the second round (retest sample), and 66 completed both rounds (test–retest sample). Reliability was evaluated using intraclass correlation (ICC) and standard error of measurement (SEM), while structural validity was assessed through confirmatory factor analysis (CFA) and Mokken analyses. Convergent validity was measured using the 4-item version of the Centre for Epidemiological Studies Depression Scale (CES-DC4).

The results showed the mean sum score in the test sample was higher than in the retest sample (0.74, 95% CI: 0.06; 1.43). The limits of agreement (LoA) were broad (-4.73; 6.21). The (ICC (1,1)) was 0.79 (95% CI: 0.67; 0.87), indicating good reliability, while the SEM was 2.03 (95% CI: 1.68; 2.37). Cronbach’s alpha was 0.80 for the test and 0.81 for the retest, showing good internal consistency. The inter-item correlations and Mokken analyses supported unidimensionality. CFA did not find an acceptable fit for a 1-factor solution. Convergent validity showed a moderate correlation with the CES-DC4 (0.48).

Investigators found that the SCL-6 showed acceptable internal consistency and test-retest reliability. While CFA results were inconclusive, Mokken analyses supported unidimensionality, making the scale usable for population-based research on depressive symptoms in adolescents but not recommended for individual screening.

Source: bmcpediatr.biomedcentral.com/articles/10.1186/s12887-025-05510-1