title: Reliability and Validity of the Pittsburgh Sleep Quality Index-Serbian Translation.
abstract: The aim of this study was translating and exploring psychometric properties of Serbian Pittsburgh Sleep Quality Index (PSQI) in a sample of "good" and "bad" sleepers suffering from depression or obstructive sleep apnea (OSA). Formal translation and validation were performed on a sample of healthy controls, patients with untreated OSA, and with diagnosed major depressive disorder with evaluation of internal consistency, test-retest reliability, and construct and criterion validity. Controls and OSA subgroups were recruited from a larger sample of commercial drivers. One hundred and forty subjects, 84.3% male, 22-67 years old, were included. OSA subgroup had 59 subjects and depression subgroup had 40 subjects (22 females). Mean ± SD total PSQI was 3.5 ± 2.2 in controls, 4.9 ± 3.6 in OSA subjects, and 9.0 ± 4.9 in patients with depression. Cronbach's α for total PSQI was 0.791. Subscale scores were significantly correlated to global PSQI in all subgroups. Intraclass correlation coefficient for global PSQI was 0.997 ( p < .001). Epworth Sleepiness Scale score was significantly correlated to global PSQI (ρ = 0.333, p < .001). Three subgroups differed significantly in total PSQI and PSQI ≥ 5, even after adjustments for age and gender ( p < .001). OSA patients had higher mean PSQI than controls but not significantly ( p = .272). PSQI-reported sleep latency did not correlate with PSG-measured sleep latency ( r = .130, p = .204). Total PSQI was significantly correlated to OSA severity (ρ = 0.261, p < .05). Serbian PSQI showed good internal consistency, test-retest reproducibility, and adequate construct and criterion validity, which supports further exploration of its use as a sleep quality screening tool in different target populations.
authors.affiliation: 1 Faculty of Medicine, University of Belgrade, Belgrade, Serbia.|2 Serbian Institute of Occupational Health, Belgrade, Serbia.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Popević
authors.affiliation: 1 Faculty of Medicine, University of Belgrade, Belgrade, Serbia.|2 Serbian Institute of Occupational Health, Belgrade, Serbia.
authors.forename: Aleksandar P S
authors.initials: APS
authors.lastname: Milovanović
authors.affiliation: 1 Faculty of Medicine, University of Belgrade, Belgrade, Serbia.|3 Clinic for Psychiatry, Clinical Centre of Serbia, Belgrade, Serbia.
authors.forename: Srdjan
authors.initials: S
authors.lastname: Milovanović
authors.affiliation: 1 Faculty of Medicine, University of Belgrade, Belgrade, Serbia.|4 Clinic for Pulmonology, Clinical Centre of Serbia, Belgrade, Serbia.
authors.forename: Ljudmila
authors.initials: L
authors.lastname: Nagorni-Obradović
authors.affiliation: 5 Faculty of Medicine, Institute of Medical Physiology, University of Belgrade, Belgrade, Serbia.
authors.forename: Dejan
authors.initials: D
authors.lastname: Nešić
authors.affiliation: 6 Institute for Occupational Health of Railway Workers, Belgrade, Serbia.
authors.forename: Marija
authors.initials: M
authors.lastname: Velaga
mesh_terms: D000328:Adult; D000368:Aged; D054521:Cultural Competency; D003865:Major Depressive Disorder / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D057566:Self Report; D055771:Serbia; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology*; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D011795:Surveys and Questionnaires / Q000592:standards*; D014175:Translating
keywords: depression; polysomnography; reliability; sleep apnea; sleep quality; validity