Insomnia persistent in second and third waves of COVID-19 in Hong Kong

Clinical insomnia was reported in one-third of Hong Kong citizens during the third wave of the coronavirus disease 2019 (COVID-19) outbreak, with over 60 percent having persistent insomnia in both the second and third waves, according to a recent longitudinal follow-up study in Hong Kong.

“Our study’s results show that the elderly and those with pre-existing psychiatric disorders are particularly susceptible to sleep and mental health issues. Policy makers should design and implement a contingency plan for proper and effective mental health resource allocation to support these vulnerable patient groups during the COVID-19 pandemic,” suggested the researchers. [Int J Environ Res Public Health 2021;18:8444]

In the study, data was collected from 339 respondents (female, 67.3 percent; aged 18–39 years, 58.7 percent) enrolled in a previous cross-sectional study (n=1,138) conducted during the second wave of the COVID-19 outbreak (6–20 April 2020; first time point). Data collection was through a self-administered online survey released via email or WhatsApp between 4 and 11 August 2020 (third wave, second time point). The same questionnaires were used to assess insomnia symptoms and daytime impairment at both time points.

At baseline, a vast majority of respondents (92.0 percent) were living with family members. Social media (67.0 percent) and conventional media (61.9 percent) were the most common sources of COVID-19–related information. Most (84.4 percent) respondents reported no exposure to any confirmed case.

Compared with sleep parameters recorded during the second wave, mean wake time after sleep onset and early morning awakening were significantly increased by 8.7 minutes (p=0.004) and 15.1 minutes (p<0.001), respectively, during the third wave. Furthermore, mid-sleep point was significantly pushed forward by 14 minutes (p<0.001), along with significant reductions in average total sleep time and sleep efficiency by 0.2 hours (p=0.03) and 4.5 percent (p<0.001), respectively.

No significant difference in the proportion of respondents having clinical insomnia was detected between the third and second waves (33.6 percent vs 33.4 percent; p=0.83). Among those with clinical insomnia, 67.0 percent reported persistence of insomnia in both the second and third waves. Sleep improved in only 10.9 percent of respondents across the two time points.

Although a significant reduction of mean Generalized Anxiety Disorder 7-item (GAD-7) score was observed during the third vs second wave (4.8 vs 5.2; p=0.047), there was no significant difference in the proportion of respondents suffering from clinical anxiety (GAD-7 ≥10) (15.3 percent vs 18.3 percent; p=0.22) across the two time points. The mean Patient Health Questionnaire-9 (PHQ-9) score was 5.8, with 22.0 percent of respondents graded as having clinical depression.

Significantly fewer respondents reported a lower level of confidence in self-protection (57.6 percent vs 64.4 percent; p=0.044) during the third vs second wave, while the same level of confidence was reported in the ability of healthcare professionals (p=1.00) and the government (p=0.14) in combating COVID-19.

Middle-aged (40–59 years) respondents were 4.03 times more likely to maintain good sleep quality across the second and third waves than those aged ≥60 years (adjusted odds ratio [OR], 4.03; 95 percent confidence interval [CI], 1.04 to 15.73, p=0.045).

Respondents with vs without history of psychiatric disorder had a 7.12-fold increase in risk of anxiety across the second and third waves (adjusted OR, 7.12; 95 percent CI, 1.33 to 38.03, p=0.02).