Table 2.

Pittsburgh Sleep Quality Index (n=75)

Variablea	Possible range	Mean	CI	Range
Subjective sleep quality	0–3	1.2	1.0–1.4	0–3
Sleep latency	0–3	0.96	0.94–0.98	0–3
Sleep duration	0–3	0.75	0.61–0.89	0–3
Habitual sleep efficiency	0–3	0.87	0.65–1.09	0–3
Sleep disturbances	0–3	1.4	1.3–1.5	0–3
Use of sleep medications	0–3	0.96	0.66–1.26	0–3
Daytime dysfunction	0–3	0.77	0.62–0.92	0–2
Totalb	0–21	7.0	6.2–7.8	0–16

^aSubscales: subjective sleep quality is the self-evaluated global satisfaction of sleep quality; sleep latency, self-reported time it takes to fall asleep after lights out; duration, self-reported actual sleep time during night; habitual sleep efficiency, number of hours reported in sleeping divided by the number of hours reported in bed multiplied by 100; sleep disturbances, usual reasons that interfere nighttime sleep; sleep medications, the frequency of use of medicine to help sleep; and daytime dysfunction, the influence of sleepiness on daytime performance

^bA total score above 5 is generally considered poor sleep