Correlates of daytime sleepiness and insomnia among adults in Samoa

ABSTRACT: Objective: To describe daytime sleepiness and insomnia among adults in Samoa and identify modifiable factors associated with these measures. Design/setting: Cross-sectional analysis of data from the Soifua Manuia (“Good Health”) study (n = 519, 55.1% female); Upolu island, Samoa. Methods: Daytime sleepiness and insomnia were assessed with the Epworth Sleepiness Scale (ESS) and the Women's Health Initiative Insomnia Rating Scale (WHIIRS), respectively. Detailed physical, sociodemographic, and behavioral factors were collected. Sleep measures were characterized using multiple linear regression with backwards elimination and a bootstrap stability investigation. Results: Excessive daytime sleepiness (ESS>10) and insomnia (WHIIRS>10) were reported by 20% and 6.3% of the sample, respectively. ESS scores were higher in individuals reporting more physical activity (Estimate=1.88; 95% CI=1.12 to 2.75), higher material wealth (0.18; 0.09 to 0.28), and asthma (2.85; 1.25 to 4.51). ESS scores were lower in individuals residing in periurban versus urban regions (-1.43; -2.39 to -0.41), reporting no work versus day shift work (-2.26; -3.07 to -1.41), and reporting greater perceived stress (-0.14; -0.23 to -0.06). WHIIRS scores were lower in individuals reporting “other” shift work (split/irregular/on-call/rotating) versus day shift work (-1.96; -2.89 to -1.14) and those who perceived their village's wealth to be poor/average versus wealthy (-0.94; -1.50 to -0.34). Conclusions: Participants had a generally higher prevalence of excessive daytime sleepiness, but lower prevalence of insomnia, compared with individuals from high-income countries. Factors associated with sleep health differed compared with prior studies, emphasizing potential cultural/environmental differences and the need for targeted interventions to improve sleep health in this setting.