Psychometric properties of the Persian version of the Grief Impairment Scale

This study validated a Persian translation of the Grief Impairment Scale (GIS) in a sample of 548 grieving Iranian adults. Researchers recruited participants online using convenience and targeted sampling and asked them to complete the GIS and other measures. Of the 548 participants, 150 completed the scales again at Time 2 after one month using anonymous identifiers. Confirmatory factor analysis supported the unidimensionality of the Persian GIS. Measurement invariance held across gender. The GIS demonstrated good internal consistency (omega = .86) and test-retest reliability (ICC =.842). Convergent validity was evidenced by strong correlations with measures of prolonged grief and functional impairment. Divergent validity was supported by weaker correlations with anxiety and depression. A cut-score of >= 7 yielded good sensitivity (87%) and specificity (71%) in identifying those with significant functional impairment from grief. The Persian GIS demonstrated excellent psychometric properties as a brief tool for assessing grief-related impairment.