Validity of the Pittsburgh Sleep Quality Index (PSQI) among Nigerian university students

Objectives: Sleep-related problems and detection of them remain largely an unidentified public health issue, especially among university students. This study aims to assess the validity of the Pittsburgh Sleep Quality Index (PSQI) among Nigerian university students. Methods: Five hundred and twenty students completed the PSQI, the 12-item General Health Questionnaire (GHQ-12) and questionnaires pertaining to socio-demographic details. The students were then interviewed for the diagnosis of insomnia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) and the International Classification of Sleep Disorders, revised criteria (ICSD-R). Results: The PSQI was of moderate value in screening for insomnia, with the best cut-off score at 5 (sensitivity 0.720, specificity 0.545, overall correct classification rate 0.554). The correlation between the PSQI and the GHQ-12 was 0.252 (p < 0.001). A 3-factor model was generated by principal component analysis. Conclusion: The psychometric value of PSQI in screening for insomnia among Nigerian students was moderate compared to what has been obtained in Western cultures. Nonetheless, it is still a useful instrument in the detection of sleep problems in this population. (c) 2006 Elsevier B.V. All rights reserved.