2.5 Assessment of sleep quality
The Pittsburgh Sleep Quality Index (PSQI) is an effective indicator of sleep quality and patterns. Subjective sleep quality, sleep latency, sleep length, habitual sleep efficiency, sleep disruptions, use of sleep medications, and daytime dysfunction were evaluated. Each factor was weighted from 0 to 3, resulting in a global score between 0 and 21. Poor sleep quality was defined as a global PSQI score of >517.