The Sleep Quality of Han Chinese and Tibetan Firefighters at High Altitude: A Field Study

The sleep quality of Han Chinese and Tibetan firefighters at high altitude remains poorly understood. This study investigates the prevalence of sleep disturbances in these groups and whether ethnicity affects sleep quality in these two populations.

Male firefighters were recruited from China Fire and Rescue stations at high altitude of 500 m, 2570 m, and 4509 m in Southwest China. The Pittsburgh Sleep Quality Index (PSQI) assessed sleep quality, considering scores >5 as poor sleep quality. Symptoms of anxiety and depression were evaluated using the 7-item Generalized Anxiety Disorder Questionnaire (GAD-7) and the 9-item Patient Health Questionnaire (PHQ-9).

As altitude increased, the total PSQI scores of Han Chinese firefighters showed a non-statistically significant rise: 4 (2-5) at 500 m, 4 (3-6.75) at 2570 m, and 5 (2.75-6) at 4509 m. Poor sleep quality prevalence also rose: 23%, 31%, and 44%, respectively. In contrast, the sleep quality of Tibetan firefighters remained relatively stable and was better than that of their Han Chinese counterparts. Furthermore, the GAD-7 and PHQ-9 scores were higher in Han Chinese firefighters compared to Tibetan firefighters. The PSQI score was positively correlated with GAD-7 scores (ρ = 0.454, p < 0.001) and PHQ-9 scores (ρ = 0.380, p < 0.001) but negatively correlated with Tibetan ethnicity (ρ = -0.228, p < 0.001). Logistic regression analysis indicated that, compared to Tibetans, being Han Chinese (odds ratio [OR] = 3.050, 95% confidence interval [CI]: 1.214-7.665) and having higher GAD-7 scores (OR = 1.816, 95% CI: 1.332-2.477) were independently associated factors for poor sleep quality.

This study suggests that Han Chinese firefighters in this field sample across these stations are at greater risk of poor sleep quality than Tibetan firefighters, with elevated GAD-7 scores being a potential contributing factor for poor sleep quality.