Prevalence of insomnia and feasibility of a nurse-administered digital cognitive behavioural therapy two years after corona virus disease hospitalisation

Background: Disturbed sleep is prevalent after corona virus disease (COVID-19). However, little is known of post infectious prevalence, course, predictors and treatment of chronic insomnia.

Aim: To estimate the prevalence of chronic insomnia three and twelve months after hospitalisation for COVID-19, to identify predictors of chronic insomnia, and to evaluate the feasibility of a nurse-administered digital cognitive behavioural therapy for insomnia (dCBTi) protocol.

Method: Patients hospitalised at Akershus University Hospital (Norway) for COVID-19 between February-June 2020 were eligible. The 94 patients that consented to participate were contacted by phone and interviewed with a modified DUKE structured interview three- and twelve months after discharge. Participants with chronic insomnia after twelve months were offered a nurse-administered dCBTi treatment protocol. Outcome measurements were sleep efficiency (SE) calculated by standard formulas (0-100 %) and the Bergen Insomnia Scale (BIS) (0-42).

Results: At three-month follow-up, 22 persons (23 %) fulfilled the diagnostic criteria for chronic insomnia. At twelve-month follow-up, 23 fulfilled the diagnostic criteria. The odds ratios for chronic insomnia after twelve months were 0.857 (0.742-0.989) for body mass index (BMI), and 0.239 (0.069-0.821) for male sex. Ten participated in the dCBTi feasibility study. Five completed the treatment protocol. SE improved, but not significantly. The BIS score improved significantly from 24 to 12 (p-value = 0.036).

Conclusion: Chronic insomnia remained stable three- and twelve months post COVID-19 hospitalisation. Female sex and low BMI were independent predictors of chronic insomnia twelve months post infection, but only 50 % of participants completed the protocol. Completers significantly reduced insomnia symptoms.