Validity and Reliability of the Greek Version of Pittsburgh Sleep Quality Index in Chronic Non-Specific Low Back Pain Patients.

ABSTRACT

The purpose of this study was to investigate psychometric properties of the Greek translation of Pittsburgh Sleep Quality Index (GR-PSQI) in a Greek chronic non-specific low back pain (CNSLBP) sample, thus, providing insight on its clarity and acceptability as a widely used sleep assessment tool in clinical practice. Asymptomatic volunteers (n = 73) and CNSLBP volunteers (n = 47), participated in the study. For the assessment of construct validity, the known-groups method was used. Thus, all the participants (asymptomatic and CNSLBP) completed the GR-PSQI. For the assessment of concurrent validity, the CNSLBP participants additionally completed the following validated questionnaires for depression, insomnia and sleep quality Beck Depression Inventory Questionnaire (BDI), Insomnia Severity Index (ISI), and Sleep Quality Numeric Rating Scale (SQNRS). For the assessment of test-retest reliability, the CNSLBP participants completed the GR-PSQI a second time, one week after the first time. The results showed excellent test-retest reliability (ICC = 0.969, SEM = 0.90, SDD = 2.49%) and internal consistency (Cronbach α = 0.985), moderate to good concurrent validity (from r = 0.556 to r = 0.860) among PSQI, BDI, SQNRS, and ISI, as well as excellent construct validity (p = 0.000) between the two groups. The Greek translation of PSQI could be a valuable tool for Greek healthcare professionals in both clinical and research environments.