Sleep Condition Indicator

The Sleep Condition Indicator (SCI) is an 8-item self-report scale designed to assess the severity of insomnia symptoms in adults in a manner closely aligned with DSM-5 diagnostic criteria for insomnia disorder. Developed by Espie and colleagues in 2014, it measures the core features of insomnia: difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, daytime impairment, and associated distress. The SCI is increasingly used in clinical practice and research to screen for insomnia, monitor treatment response, and evaluate cognitive-behavioral therapy efficacy.