Sleep Quality Mediates the Effect of Sensitization-Associated Symptoms, Anxiety, and Depression on Quality of Life in Individuals with Post-COVID-19 Pain

Abstract

A better understanding of biological and emotional variables associated with health-related quality of life in people with long-COVID is needed. Our aim was to identify potential direct and indirect effects on the relationships between sensitization-associated symptoms, mood disorders such as anxiety/depressive levels, and sleep quality on health-related quality of life in people suffering from post-COVID-19 pain. One hundred and forty-six individuals who were hospitalized due to COVID-19 during the first wave of the pandemic and suffering from long-term post-COVID-19 pain completed different patient-reported outcome measures (PROMs), including clinical features, symptoms associated with sensitization of the central nervous system (Central Sensitization Inventory), mood disorders (Hospital Anxiety and Depressive Scale), sleep quality (Pittsburgh Sleep Quality Index), and health-related quality of life (paper-based five-level version of EuroQol-5D) in a face-to-face interview conducted at 18.8 (SD 1.8) months after hospitalization. Different mediation models were conducted to assess the direct and indirect effects of the associations among the different variables. The mediation models revealed that sensitization-associated symptoms and depressive levels directly affected health-related quality of life; however, these effects were not statistically significant when sleep quality was included. In fact, the effect of sensitization-associated symptomatology on quality of life (β = -0.10, 95% CI -0.1736, -0.0373), the effect of depressive levels on quality of life (β= -0.09, 95% CI -0.1789, -0.0314), and the effect of anxiety levels on quality of life (β = -0.09, 95% CI -0.1648, -0.0337) were all indirectly mediated by sleep quality. This study revealed that sleep quality mediates the relationship between sensitization-associated symptoms and mood disorders (depressive/anxiety levels) with health-related quality of life in individuals who were hospitalized with COVID-19 at the first wave of the pandemic and reporting post-COVID-19 pain. Longitudinal studies will help to determine the clinical implications of these findings.

Keywords: anxiety; depression; post-COVID-19; quality of life; sensitization; sleep.

Figure 1

Mediation models with standardized coefficients. Model 1. a₁ = beta value of sensitization-associated symptoms on sleep quality; b₁ = beta value of sleep quality on quality of life; c₁ = total effect of sensitization-associated symptoms on quality of life; c₁’ = direct effect of sensitization-associated symptoms on quality of life once sleep quality is included in the model. Model 2. a₂ = beta value of depressive levels on sleep quality; b₂ = beta value of sleep quality on quality of life; c₂ = total effect of depressive levels on quality of life; c₂’ = direct effect of depressive levels on quality of life once sleep quality has been included in the model. Model 3. a₃ = beta value of anxiety on sleep quality; b₃ = beta value of sleep quality on quality of life; c₃= total effect of anxiety on quality of life; c₃’ = direct effect of anxiety on quality of life once sleep quality has been included in the model. * p < 0.05; ** p < 0.01.