Background: The applicability of the Pittsburgh Sleep Quality Index (PSQI) in screening of insomnia is demonstrated in various populations. But, the tool has not been validated in a sample of Ethiopians. Therefore, this study aimed to assess its psychometric properties in community dwelling Ethiopian adults.
Material and methods: Participants (n = 311, age = 25.5 ± 6.0 years and body mass index = 22.1 ± 2.3 kg/m2) from Mizan-Aman town, Southwest Ethiopia completed the PSQI and a semi-structured questionnaire for socio-demographics. Clinical interview for screening of insomnia according to the International Classification of Sleep Disorders was carried out as a concurrent validation measure.
Results: Overall, the PSQI scale did not have floor effect and ceiling effects. Moderate internal consistency (Cronbach's alpha was 0.59) and sufficient internal homogeneity as indicated by correlation coefficient between component scores and the global PSQI score was found. The PSQI was of good value for screening insomnia with optimal cut-off scores of 5.5 (sensitivity 82%, specificity 56.2%) and the area under the curve, 0.78 (p < 0.0001). The PSQI has unidimensional factor structure in the Ethiopian community adults for screening insomnia.
Conclusion: The PSQI has good psychometric validity in screening for insomnia among Ethiopians adults.
Keywords: Catha edulis; Ethiopia; Insomnia; PSQI; Pittsburgh sleep quality index; Sleep; Substance abuse.