Biopsychosocial factors associated with health-related quality of life in long COVID: a matched case–control study in primary care
BACKGROUND
Long COVID is associated with persistent symptoms, functional impairment, and reduced health-related quality of life (HRQoL), but the factors most strongly associated with poorer HRQoL remain incompletely characterized. This study compared adults with long COVID and recovered controls and identified variables independently associated with worse HRQoL.
METHODS
We conducted a case–control analysis of the ARALONGCOV 2022 dataset including 170 adults with prior COVID-19: 85 with long COVID and 85 recovered controls without persistent symptoms. HRQoL was assessed with the 12-item Short Form Health Survey (SF-12) total score. Additional measures included depressive symptoms (Patient Health Questionnaire-9, PHQ-9), fatigue severity (Fatigue Severity Scale, FSS), sleep quality (Pittsburgh Sleep Quality Index, PSQI), pain catastrophizing, post-COVID functional status (PCFS), physical activity, and distance completed during the six-minute walk test (6MWT-D). Between-group comparisons used Mann–Whitney U tests for continuous variables and chi-squared or Fisher exact tests for categorical variables. Univariable and multivariable linear regression models were fitted within long COVID cases to identify factors independently associated with SF-12 total score.
RESULTS
Compared with recovered controls, participants with long COVID had markedly worse HRQoL (median SF-12 28.75 [IQR 21.25–39.17] vs 73.96 [62.81–77.50]; p < 0.001), more depressive symptoms (PHQ-9: 12.00 [7.00–18.00] vs 2.00 [0.00–6.00]; p < 0.001), greater fatigue (FSS: 57.00 [50.00–62.00] vs 13.00 [9.00–33.00]; p < 0.001), worse sleep quality (PSQI: 14.00 [9.00–16.00] vs 6.00 [3.00–11.00]; p < 0.001), and shorter 6MWT-D (481 [406–560] m vs 556 [491–609] m; p < 0.001). Long COVID cases were also less frequently employed (38.8% vs 81.2%; p < 0.001) and had more post-COVID comorbidity (88.2% vs 60.0%; p < 0.001). In the multivariable model within long COVID cases (n = 85), active employment was independently associated with better HRQoL (B 5.315, 95% CI 0.610 to 10.021; p = 0.027), whereas depressive symptoms (B − 1.124, 95% CI − 1.500 to − 0.748; p < 0.001) and post-COVID comorbidity count (B − 1.252, 95% CI − 2.484 to − 0.021; p = 0.046) were independently associated with worse HRQoL. Fatigue severity showed a borderline association in the same direction (B − 0.171, 95% CI − 0.343 to + 0.001; p = 0.051). The model explained 48.9% of the variance in SF-12 score within long COVID cases (R2 = 0.489; adjusted R2 = 0.463). Exploratory clustering did not identify discrete phenotypes; the burden distribution was more consistent with a continuous severity gradient. For descriptive purposes, a lower-burden stratum (33/78, 42.3%) and a higher-burden stratum (45/78, 57.7%) were operationalized and differed across symptom load, fatigue, mood, functional status, exercise capacity, and HRQoL.
CONCLUSIONS
Long COVID was associated with profound impairment in HRQoL compared with recovered controls. Depressive symptoms, post-COVID comorbidity burden, and lower active employment were the strongest independent correlates of poorer HRQoL; fatigue severity showed a borderline association in the same direction. These findings support multidisciplinary long COVID care models that integrate symptom control, mental health assessment, and social and occupational reintegration. Routine assessment of fatigue, depressive symptoms, post-COVID multimorbidity, and occupational status may help identify long COVID patients with the most severe concurrent HRQoL impairment, though longitudinal confirmation is needed to establish predictive utility.
TRIAL REGISTRATION
Trial registration: ISRCTN registry, identifier ISRCTN27312680.
Web | DOI | PDF | BMC Primary Care | Open Access
Lerma-Irureta, David; Presa-Gutiérrez, Elsa; Méndez-López, Fátima; Vicente-García, Carmen; Blasco-González, Isabel; Magallón-Botaya, Rosa
BACKGROUND
Long COVID is associated with persistent symptoms, functional impairment, and reduced health-related quality of life (HRQoL), but the factors most strongly associated with poorer HRQoL remain incompletely characterized. This study compared adults with long COVID and recovered controls and identified variables independently associated with worse HRQoL.
METHODS
We conducted a case–control analysis of the ARALONGCOV 2022 dataset including 170 adults with prior COVID-19: 85 with long COVID and 85 recovered controls without persistent symptoms. HRQoL was assessed with the 12-item Short Form Health Survey (SF-12) total score. Additional measures included depressive symptoms (Patient Health Questionnaire-9, PHQ-9), fatigue severity (Fatigue Severity Scale, FSS), sleep quality (Pittsburgh Sleep Quality Index, PSQI), pain catastrophizing, post-COVID functional status (PCFS), physical activity, and distance completed during the six-minute walk test (6MWT-D). Between-group comparisons used Mann–Whitney U tests for continuous variables and chi-squared or Fisher exact tests for categorical variables. Univariable and multivariable linear regression models were fitted within long COVID cases to identify factors independently associated with SF-12 total score.
RESULTS
Compared with recovered controls, participants with long COVID had markedly worse HRQoL (median SF-12 28.75 [IQR 21.25–39.17] vs 73.96 [62.81–77.50]; p < 0.001), more depressive symptoms (PHQ-9: 12.00 [7.00–18.00] vs 2.00 [0.00–6.00]; p < 0.001), greater fatigue (FSS: 57.00 [50.00–62.00] vs 13.00 [9.00–33.00]; p < 0.001), worse sleep quality (PSQI: 14.00 [9.00–16.00] vs 6.00 [3.00–11.00]; p < 0.001), and shorter 6MWT-D (481 [406–560] m vs 556 [491–609] m; p < 0.001). Long COVID cases were also less frequently employed (38.8% vs 81.2%; p < 0.001) and had more post-COVID comorbidity (88.2% vs 60.0%; p < 0.001). In the multivariable model within long COVID cases (n = 85), active employment was independently associated with better HRQoL (B 5.315, 95% CI 0.610 to 10.021; p = 0.027), whereas depressive symptoms (B − 1.124, 95% CI − 1.500 to − 0.748; p < 0.001) and post-COVID comorbidity count (B − 1.252, 95% CI − 2.484 to − 0.021; p = 0.046) were independently associated with worse HRQoL. Fatigue severity showed a borderline association in the same direction (B − 0.171, 95% CI − 0.343 to + 0.001; p = 0.051). The model explained 48.9% of the variance in SF-12 score within long COVID cases (R2 = 0.489; adjusted R2 = 0.463). Exploratory clustering did not identify discrete phenotypes; the burden distribution was more consistent with a continuous severity gradient. For descriptive purposes, a lower-burden stratum (33/78, 42.3%) and a higher-burden stratum (45/78, 57.7%) were operationalized and differed across symptom load, fatigue, mood, functional status, exercise capacity, and HRQoL.
CONCLUSIONS
Long COVID was associated with profound impairment in HRQoL compared with recovered controls. Depressive symptoms, post-COVID comorbidity burden, and lower active employment were the strongest independent correlates of poorer HRQoL; fatigue severity showed a borderline association in the same direction. These findings support multidisciplinary long COVID care models that integrate symptom control, mental health assessment, and social and occupational reintegration. Routine assessment of fatigue, depressive symptoms, post-COVID multimorbidity, and occupational status may help identify long COVID patients with the most severe concurrent HRQoL impairment, though longitudinal confirmation is needed to establish predictive utility.
TRIAL REGISTRATION
Trial registration: ISRCTN registry, identifier ISRCTN27312680.
Web | DOI | PDF | BMC Primary Care | Open Access