Sleep quality affects life satisfaction in military personnel: the chain mediating effects of non-attachment and rumination

The military population, due to special occupational stress and high-intensity tasks, commonly experiences sleep problems, which may have a negative impact on life satisfaction; however, the underlying mechanism remains unclear. This study aims to explore the effect of sleep quality on life satisfaction among military personnel and the roles of non-attachment and rumination in the relationship between sleep quality and life satisfaction.

A cross-sectional study design was adopted without prospective grouping or intervention. A total of 1352 military personnel from a certain unit were selected using convenience sampling. The survey instruments included the Pittsburgh Sleep Quality Index, the Satisfaction with Life Scale, the Non-Attachment Scale, and the Ruminative Response Scale. Statistical analyses included: descriptive statistics to analyze the demographic characteristics of variables; Spearman correlation analysis to examine the correlations among the variables; Linear regression was used to analyze the linear relationships of sleep quality with non-attachment, rumination, and life satisfaction;and PROCESS macro Model 6 in SPSS to estimate regression coefficients (β) and their 95% confidence intervals (CIs) using Bootstrap method, in order to test the chain mediating effect of non-attachment and rumination in the relationship between sleep quality and life satisfaction.

Military personnel aged ≥29 years had significantly higher sleep quality scores than those aged 18 to 28 years (P<0.05). Military personnel aged 18 to 23 years exhibited significantly higher rumination scores than those aged 24 years (P<0.05). Military personnel with bachelor’s degree or above had significantly higher sleep quality and rumination scores than those with college degree or high school and below (P<0.01). In terms of non-attachment scores, military personnel with a bachelor’s degree or above had significantly lower non-attachment scores than those with college degree or below (P<0.01). Military personnel with bachelor’s degree or above had significantly lower life satisfaction scores than those with college degree (P<0.05). Correlation analysis revealed that sleep quality was significantly negatively correlated with non-attachment (r=-0.395, 95%CI: -0.441 to -0.348, P<0.001) and life satisfaction (r=-0.407, 95%CI: -0.452 to -0.361, P<0.001), and positively with rumination (r=0.440, 95%CI: 0.395 to 0.483, P<0.001). Non-attachment was significantly negatively correlated with rumination (r=-0.508, 95%CI: -0.547 to -0.466, P<0.001) and positively with life satisfaction (r=0.515, 95%CI: 0.473 to 0.554, P<0.001), and rumination was significantly negatively correlated with life satisfaction (r=-0.442, 95%CI: -0.485 to -0.397, P<0.001). The linear regression showed that sleep quality significantly negatively predicted life satisfaction (β=-0.456, P<0.001); non-attachment significantly positively predicted life satisfaction (β=0.243, P<0.001); rumination significantly negatively predicted life satisfaction (β=-0.184, P<0.001). The total effect of sleep quality on life satisfaction was significant, with a total effect size of -0.868 (95%CI: -0.977 to -0.759, P<0.001). The mediating effects of non-attachment and rumination in the impact of sleep quality on life satisfaction were significant, with effect values of -0.172 (95%CI: -0.232 to -0.122, P<0.001) and -0.196 (95%CI: -0.251 to -0.140, P<0.001), respectively, accounting for 19.82% and 22.58% of the total effect, respectively. Non-attachment and rumination played chain mediating roles in the impact of sleep quality on life satisfaction, with an effect value of -0.044 (95%CI: -0.061 to -0.029, P<0.001), accounting for 5.07% of the total effect.

Sleep quality, non-attachment, rumination, and life satisfaction are closely related among military personnel, and sleep quality affects life satisfaction through the chain mediating effects of non-attachment and rumination. It is recommended that military psychological interventions focus on improving sleep quality, while reducing rumination and cultivating non-attachment attitudes through mindfulness training, to systematically enhance life satisfaction among military personnel.