2.4.7. Sleep quality.
daytime dysfunction
Sleep quality can be assessed through a variety of methods, including self-report questionnaire like the Pittsburgh Sleep Quality Index. Pittsburgh Sleep Quality Index consists of 19 items, evaluates the individual sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication and daytime dysfunction. The scale scores between 0 and 3 (0: no difficulty, 3: severe difficulty). The Turkish validity and reliability study of the scale was conducted by Ozturk et al in 2009.