Previously, no meta-analytical studies had been conducted that focused on the prevalence of insomnia symptoms in different COVID-19 patient groups. This review was able to evaluate insomnia symptoms while maintaining data homogeneity by using a single assessment tool.
From the pooled analysis, the estimate of insomnia symptoms, both subthreshold and clinically significant, was 52.57%. There was an estimate of 16.66% suffering from clinically significant insomnia, with 13.75% of that population suffering from moderate insomnia and 2.50% suffering from severe insomnia.1 Maha Meshal Alrasheed, PhD, MSc Associate Professor, Department of Clinical Pharmacy, College of Pharmacy, King Saud University, and colleagues that their data “suggest that the COVID-19 pandemic is specifically associated with a marked increase in the number of insomnia symptoms among the threshold but no moderate or severe insomnia.”
Seventeen databases and six preprint services of relevant studies between November 2019 and August 2021 were explored. Only studies that assessed insomnia using the Insomnia Severity Index (ISI) were included in the analysis. In total, the systematic review collected 48 studies from 25 countries and assessed 133,006 study participants with ISI for symptoms of insomnia during the COVID-19 pandemic.
Alrasheed and colleagues wrote that “a statistically significant difference was observed between countries for all insomnia symptom severity. Neither age nor gender were found to be moderators of the prevalence of cumulative prevalence of subthreshold insomnia symptoms or of clinically significant insomnia.” Taken together, the different rates of subthreshold insomnia symptoms across the different included countries were 27.27% in China (95% CI, 22.30-32.88), 28.91% in India (95% CI, 24.90- 33.28), 46.82% in Italy (95% CI, 38.24-55.61), 35.11% in Turkey (95% CI, 32.45-37.86), and 38.31% in the United States (95% CI, 28.54-49.13).1
This study is consistent with 2 other previous meta-analyses of the pooled prevalence of insomnia symptoms observed during COVID-19 (40%-50%).2.3 Many factors may have contributed to the increase in insomnia symptoms caused by the COVID-19 pandemic, including high levels of anxiety, depression, post-traumatic stress disorder and stress, which were reported by the general population worldwide when the COVID-19 pandemic occurred.4 Other factors reported as important were being female, in a younger age group, a history of psychiatric illness, unemployment, low educational status, and frequent exposure to social media/news about the pandemic.4
The strengths of Alrasheed et al’s study were that the prevalence of insomnia symptoms, by severity, was estimated in different populations using the data of individual participants. Thus, this allowed for a more accurate understanding of insomnia symptoms from the effects of COVID-19. In particular, the meta-regression and subgroup analysis provided an effective approach to the findings when examining heterogeneity. The synthesized sample size was large as participants were recruited from 25 countries, making the findings generalizable.
The study’s limitations included that there may have been bias in the estimates of insomnia prevalence, as other measures could have reflected the severity of insomnia in a different way. Another limitation is that the estimated results do not necessarily reflect the impact of COVID-19 over a specific time period and cannot be generalized to different ethnicities and age groups. In addition, the review response rate was a limitation as only about 50% of the authors agreed to participate by providing the original datasets for secondary analyses.1
Alrasheed et al noted, “Educating diverse demographics about the importance of sleep and the risk of developing insomnia symptoms during this or future pandemics should be a concern for the sleep medicine community, as well as developing measures to prevent the development of insomnia below the threshold. and its progression to more severe forms of the disorder.”