The impact of sleep quality on health, participation and employment outcomes in people with spinal cord injury: Analyses from a large cross-sectional survey

Background: Poor sleep is common in people with spinal cord injury (SCI), yet little is known about its impact on employment and participation outcomes.

Objectives: This study aimed to (1) describe the sleep quality of a large sample of Australians with SCI and compare the results to data from an adult control and other clinical populations; (2) examine associations between sleep quality and participant characteristics; and (3) explore the relationship between sleep and outcomes.

Methods: Cross-sectional data from the Australian arm of the International Spinal Cord Injury (Aus-InSCI) survey from 1579 community-dwelling people aged >18 years with SCI were analysed. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). Relationships between participant characteristics, sleep quality and other outcomes were examined with linear and logistic regression.

Results: The PSQI was completed by 1172 individuals; 68% reported poor sleep (global PSQI score >5). Subjective sleep quality in people with SCI was poor (mean PSQI = 8.5, SD 4.5) when compared to adults without SCI (PSQI = 5.00, SD 3.37) and with traumatic brain injury (PSQI = 5.54, SD 3.94). Financial hardship and problems with secondary health conditions were significantly associated with worse sleep quality (p < 0.05). Poor sleep quality was strongly associated with lower emotional wellbeing and energy, and greater problems with participation (p < 0.001). Individuals engaged in paid work reported better sleep quality (mean PSQI = 8.1, SD 4.3) than unemployed individuals (mean PSQI = 8.7, SD 4.6; p < 0.05). Following adjustment for age, pre-injury employment, injury severity and years of education, better sleep quality remained strongly associated with being employed (OR 0.95, 95% CI 0.92 to 0.98; p = 0.003).

Conclusions: This study demonstrated pervasive and impactful relationships between sleep quality and important SCI outcomes. Poor sleep quality was strongly associated with worse emotional wellbeing and vitality, unemployment and lower participation. Future studies should aim to determine whether treating sleep problems can improve outcomes for people living with SCI.