We aimed to validate the Inventory of Complicated Grief (ICG)-Korean version among 1,138 Korean adolescents, representing a response rate of 57% of 1,997 students. Participants completed a set of questionnaires including demographic variables (age, sex, years of education, experience of grief), the ICG, the Children's Depression Inventory (CDI) and the Lifetime Incidence of Traumatic Events-Child (LITE-C). Exploratory factor analysis was performed to determine whether the ICG items indicated complicated grief in Korean adolescents. The internal consistency of the ICG-Korean version was Cronbach's α=0.87. The test-retest reliability for a randomly selected sample of 314 participants in 2 weeks was r=0.75 (P<0.001). Concurrent validity was assessed using a correlation between the ICG total scores and the CDI total scores (r=0.75, P<0.001). The criterion-related validity based on the comparison of ICG total scores between adolescents without complicated grief (1.2 ± 3.7) and adolescent with complicated grief (3.2 ± 6.6) groups was relatively high (t=5.71, P<0.001). The data acquired from the 1,138 students was acceptable for a factor analysis (Kaiser-Meyer-Olkin Measure of Sampling Adequacy=0.911; Bartlett's Test of Sphericity, χ(2)=13,144.7, P<0.001). After omission of 3 items, the value of Cronbach's α increased from 0.87 for the 19-item ICG-Korean version to 0.93 for the 16-item ICG-Korean version. These results suggest that the ICG is a useful tool in assessing for complicated grief in Korean adolescents. However, the 16-item version of the ICG appeared to be more valid compared to the 19-item version of the ICG. We suggest that the 16-item version of the ICG be used to screen for complicated grief in Korean adolescents.
Keywords: Adolescent; Complicated Grief; Factor Analysis, Statistical; Reliability of Results; Screening.