Sleep disturbances among Swedish soldiers after military service abroad

Aims Since 1956, more than 100,000 Swedish soldiers have served abroad on various international missions. The aim of this paper was to determine whether there was a connection between military service abroad and sleep disorders among Swedish soldiers. Methods The prevalence of sleep disturbances among 1,080 veterans from Kosovo and Afghanistan was compared with almost 27,000 Swedes from a general population sample, using propensity score matching and logistic regression. The sleep disturbances studied were habitual snoring, difficulty inducing sleep (DIS), difficulty maintaining sleep (DMS), early morning awakenings (EMA), and excessive daytime sleepiness (EDS). Insomnia was defined as having at least one of DIS, DMS, or EMA. The covariates used in the matching and adjustments were age, gender, smoking habits, BMI, education, ever having had asthma, moist snuff, and exercise habits. Results The veterans had a significantly lower prevalence of insomnia (26.2% versus 30.4%) and EDS (22.7% versus 29.4%) compared with a matched group from the reference population, using propensity score matching. Analyses with logistic regression showed that belonging to the military population was related to a lower risk of having DMS (adjusted OR (95% CI) 0.77 (0.64-0.91)), insomnia (OR 0.82 (0.71-0.95)), and EDS (OR 0.74 (0.63-0.86)), whereas no significant difference was found for snoring, DIS, and EMA. Conclusion Swedish veterans have fewer problems with insomnia and daytime sleepiness than the general Swedish population. The explanation of our findings may be the selection processes involved in becoming a soldier and when sampling personnel for military assignments abroad.