Psychometric comparison of single-item, short, and comprehensive depression screening measures in Korean young adults

Background: Integrating long depression-screening instruments into routine clinical practice and research studies is often impractical, necessitating short-item if not single-item measures with comparable psychometric properties. Objective: To examine whether single-item or short depression-screening measures are comparable to a comprehensive screening measure in reliability (i.e., internal consistency and test-retest reliability) and validity (i.e., convergent, concurrent, and predictive validity) in Korean young adults within a Classical Testing Theory framework. Method: A total of 458 students from six nursing colleges in South Korea completed three depression measures: the 20-item Center for Epidemiologic Studies-Depression screening instrument (CES-D; comprehensive measure); the five-item Profile of Mood States-Brief depression subscale (POMS-B depression subscale; short measure); a single-item Likert measure; and a single-item numeric rating scale. Internal consistency reliability was tested by Cronbach's alpha and item-total correlations; test-retest reliability by intraclass correlation coefficient (ICC); convergent validity by correlation with the CES-D; concurrent validity by the correlation with perceived stress level and sleep quality; and predictive validity by receiver operating characteristic curve to predict the two groups with different depression levels. Results: The POMS-B depression subscale was comparable to the comprehensive CES-D scale in internal consistency reliability (alpha = .85); test-retest reliability (ICC = .76); and convergent (r = .81 with CES-D), concurrent (r = .64 with perceived stress level, r = .34 with sleep quality), and predictive validity (area under the curve = .88). The two single-item options were not comparable to the comprehensive CES-D. Conclusion: The short POMS-B depression subscale shows an acceptable balance between practical clinical and research needs and psychometric quality.