Cluster analysis of insomnia symptoms during COVID-19 pandemic: a general population web-based survey in Iran

To investigate the prevalence of insomnia and its different phenotypes as well as their association with fear of COVID-19 in the general population.

This was a cross-sectional study conducted using an online survey (e-poll). All available participants who completed the online survey form were included in the current study. All individuals with a history of sleep problems were excluded. A questionnaire package consisted of insomnia severity index (ISI), and FCV-19 for corona fear was administered for all participants. Insomnia was defined as ISI≥8. Insomnia phenotypes were considered as: (a) DIS: difficulty initiating sleep; (b) DMS: difficulty maintaining sleep; (c) EMA: early morning awakening; and (d) combined insomnia.

A total of 1,223 participants [827 (67.6%) female, mean age=39.82±10.75 years old], enrolled in the current survey. Based on ISI, 675 (55.2% [95%CI=52.40-57.98]) were categorized into the insomnia group. Insomnia was more prevalent in females (p=0.006), participants with 50 years old or higher (p=0.04), or high fear of COVID-19 (p<0.0001). Totally, 67.4%, 66.4%, and 55% of all participants had DIS, DMS, and EMA, respectively, in the current outbreak. Besides, 79% had impaired daily functioning, 51.6% had impaired quality of life, and 62% were worried about their sleep problem. Notably that a considerable percentage of individuals with normal ISI scores had at least one insomnia phenotype or impaired daily functioning and quality of life. Further analyses revealed a significant increasing trend in all four insomnia phenotypes prevalence with an increase in fear of COVID-19 (all p-values<0.0001).

Individuals with higher age, female gender, or higher fear of COVID-19 are at higher risk of all types of insomnia as well as impaired daytime performance or quality of life.