Associations between sleep quality and domains of quality of life in a non-clinical sample: results from higher education students.

OBJECTIVE: The association between sleep quality and quality of life (QoL) in clinical samples diagnosed with sleep disorders, mental disorders, or other medical conditions has been widely investigated. However, few studies focused on this relationship in samples of mostly young and healthy adults. This study analyzed the associations between sleep quality and several dimensions of QoL in higher education students and examined whether or not sleep quality would significantly predict QoL after statistically controlling for psychopathological symptoms.

DESIGN: Observational and transversal.

SETTING: Non-clinical; higher education.

PARTICIPANTS: A sample of 324 college students, aged 17 to 47 years (M=20.89±2.85) were enrolled.

MEASUREMENTS: European Portuguese versions of the Pittsburgh Sleep Quality Index (PSQI), the WHOQOL-Bref to measure QoL, and the Brief Symptom Inventory (BSI) to measure psychopathological symptoms.

RESULTS: All PSQI components were significantly associated with general QoL and the psychological and physical QoL domains. The subjective sleep quality and daytime dysfunction PSQI components were consistently associated with all WHOQOL-Bref domains and general QoL. Hierarchical regression analyses further showed that the PSQI components as a whole, and in particular subjective sleep quality, added significant contributions to the general QoL facet and to the psychological, physical, and environmental QoL domains, after controlling for psychopathological symptoms.

CONCLUSIONS: Several components of sleep quality and different facets/domains of QoL are associated in higher education students, particularly subjective sleep quality, which remains a significant predictor of most aspects of QoL, regardless of the presence of psychopathological symptoms.