BackgroundThe coronavirus infectious disease (COVID-19) pandemic is an ongoing global health care challenge. Up to one third of hospitalised patients develop severe pulmonary complications and ARDS. Pulmonary outcomes following COVID-19 are unknown.MethodsThe Swiss COVID-19 lung study is a multicentre prospective cohort investigating pulmonary sequela of COVID-19. We report on initial follow-up 4 months after mild/moderate or severe/critical COVID-19 according to the WHO severity classification.Results113 COVID-19 survivors were included (mild/moderate 47, severe/critical 66). We confirmed several comorbidities as risk factors for severe/critical disease. Severe/critical disease was associated with impaired pulmonary function, i.e. diffusing capacity (DLCO) %-predicted, reduced 6-MWD, and exercise-induced oxygen desaturation. After adjustment for potential confounding by age, sex, and BMI, patients after severe/critical COVID-19 had a 20.9 (95% CI 12.4–29.4, p=0.01) lower DLCO %-predicted at follow up. DLCO %-predicted was the strongest independent factor associated with previous severe/critical disease when age, sex, BMI, 6MWD, and minimal SpO2 at exercise, were included in the multivariable model (adjusted odds ratio [OR] per 10%-predicted 0.59 [95% CI 0. 37–0.87], p=0.01). Mosaic hypoattenuation on chest computed tomography at follow-up was significantly associated with previous severe/critical COVID-19 including adjustment for age and sex (adjusted OR 11.7 [95%CI 1.7–239), p=0.03).ConclusionsFour months after SARS CoV-2 infection, severe/critical COVID-19 was associated with significant functional and radiological abnormalities, potentially due to small airway and lung parenchymal disease. A systematic follow-up for survivors needs to be evaluated to optimise care for patients recovering from COVID-19.

BackgroundLung function is an important predictor of health and a marker of physical functioning at older ages. This study aimed to quantify the years of lung function lost according to disadvantaged socioeconomic conditions across life-course.MethodsThis multicohort study used harmonised individual-level data from six European cohorts with information on life-course socioeconomic disadvantage and lung function assessed by FEV1 and FVC. 70496 participants (51% women) aged 18–93 years were included. Socioeconomic disadvantage was measured in early life (low paternal occupational position), early adulthood (low educational level), and adulthood (low occupational position). Risk factors for poor lung function (e.g., smoking, obesity, sedentary behaviour, cardiovascular and respiratory diseases) were included as potential mediators. The years of lung function lost due to socioeconomic disadvantage were computed at each life stage.ResultsSocioeconomic disadvantage during life-course was associated with a lower FEV1. By age 45, individuals experiencing disadvantaged socioeconomic conditions had lost 4 to 5 years of healthy lung function versus their more advantaged counterparts (low educational level: −4.36 [95% CI −7.33; −2.37] for men and −5.14 [−10.32; −2.71] for women; low occupational position: −5.62 [−7.98; −4.90] for men and −4.32 [−13.31; −2.27] for women), after accounting for the risk factors for lung function. By ages 65 and 85, the years lung function lost due to socioeconomic disadvantage decreased by 2 to 4 years, depending on the socioeconomic indicator. Sensitivity analysis using FVC yielded similar results to those using FEV1.ConclusionLife-course socioeconomic disadvantage is associated with lower lung function and predicts a significant number of years of lung function loss in adulthood and older ages.

BackgroundThe Clinical Frailty Scale (CFS) is increasingly used for clinical decision making in acute care but little is known about frailty after COVID-19.ObjectivesTo investigate frailty and the CFS for post-COVID-19 follow-up.MethodsThis prospective multicentre cohort study included COVID-19 survivors aged ≥50 years presenting for a follow-up visit ≥3 months after the acute illness. Nine centres retrospectively collected pre-COVID-19 CFS and prospectively CFS at follow-up. Three centres completed the Frailty Index (FI), the short physical performance battery (SPPB), 30 s sit-to-stand test and handgrip strength measurements. Mixed effect logistic regression models accounting for repeated measurements and potential confounders were used to investigate factors associated with post-COVID-19 CFS. Criterion and construct validity were determined by correlating the CFS to other concurrently assessed frailty measurements and measures of respiratory impairment, respectively.ResultsOf the 288 participants 65% were men, mean (SD) age was 65.1 (9) years. Median (IQR) CFS at follow-up was 3 (2–3), 21% were vulnerable or frail (CFS ≥4). The CFS was responsive to change, correlated with the FI (r=0.69, p<0.001), the SPPB score (r=−0.48, p<0.001) (criterion validity) and with the St George’s Respiratory Questionnaire score (r=0.59, p<0.001), forced vital capacity %-predicted (r=−0.25, p<0.001), 6 min walk distance (r=−0.39, p<0.001) and modified Medical Research Council (mMRC) (r=0.59, p<0.001). Dyspnoea was significantly associated with a higher odds for vulnerability/frailty (per one mMRC adjusted OR 2.01 (95% CI 1.13 to 3.58), p=0.02).ConclusionsThe CFS significantly increases with COVID-19, and dyspnoea is an important risk factor for post-COVID-19 frailty and should be addressed thoroughly.

<b><i>Background:</i></b> Lung function impairment persists in some patients for months after acute coronavirus disease 2019 (COVID-19). Long-term lung function, radiological features, and their association remain to be clarified. Objectives: We aimed to prospectively investigate lung function and radiological abnormalities over 12 months after severe and non-severe COVID-19. <b><i>Methods:</i></b> 584 patients were included in the Swiss COVID-19 lung study. We assessed lung function at 3, 6, and 12 months after acute COVID-19 and compared chest computed tomography (CT) imaging to lung functional abnormalities. <b><i>Results:</i></b> At 12 months, diffusion capacity for carbon monoxide (DLCO_corr) was lower after severe COVID-19 compared to non-severe COVID-19 (74.9% vs. 85.2% predicted, <i>p</i> &#x3c; 0.001). Similarly, minimal oxygen saturation on 6-min walk test and total lung capacity were lower after severe COVID-19 (89.6% vs. 92.2%, <i>p</i> = 0.004, respectively, 88.2% vs. 95.1% predicted, <i>p</i> = 0.011). The difference for forced vital capacity (91.6% vs. 96.3% predicted, <i>p</i> = 0.082) was not statistically significant. Between 3 and 12 months, lung function improved in both groups and differences in DLCO between non-severe and severe COVID-19 patients decreased. In patients with chest CT scans at 12 months, we observed a correlation between radiological abnormalities and reduced lung function. While the overall extent of radiological abnormalities diminished over time, the frequency of mosaic attenuation and curvilinear patterns increased. <b><i>Conclusions:</i></b> In this prospective cohort study, patients who had severe COVID-19 had diminished lung function over the first year compared to those after non-severe COVID-19, albeit with a greater extent of recovery in the severe disease group.