Insomnia symptoms during the covid-19 pandemic: a case-control study

To identify lifestyle-related, sociodemographic, and mental health characteristics of people with insomnia symptoms and people without insomnia during the pandemic.

A case-control study was conducted with data collected by snowball sampling using an online questionnaire. From November 2020 to April 2021, 6,360 people with a mean age of 43.5 years (SD = 14.3) participated in the survey. For this study, we considered 158 cases of insomnia disorder and 476 controls (three controls per case) randomly selected from the participants without sleep problems.

The results of the comparative analysis between cases and controls showed that sleeping less than six hours daily (OR = 3.89; 95%CI 2.50-6.05), feeling sadness frequently (OR = 2.95; 95%CI 1.69-5.17), residing in metropolitan areas (OR = 1.71; 95%CI 1.04-2.84), being 40 years or older (OR = 1.93; 95%CI 1.22-3.06), and the interaction between occupation and poorer education (OR = 2.12; 95%CI 1.22-3.69) were predictors for symptoms of insomnia disorder during the pandemic.

In addition to confirming the hypothesis that mental health problems are associated with insomnia symptoms, the results point to insomnia as an important outcome for studies on the effects of unemployment, vulnerability and low education of the population, especially in large cities, highlighting that the effects of the crisis on health and the economy are extremely unequally distributed.