Functionality and quality of life in the follow-up of patients with post-COVID-19 syndrome

Abstract

Introdução: In late 2019, a distinct evolution of pneumonia cases in China caused by Severe Acute Respiratory Syndrome Coronavirus 2 triggered a pandemic declared by the World Health Organization with a high rate of transmissibility and wide spread, the Coronavirus 2019 disease (COVID-19). The main symptoms identified in the acute phase of the disease are related to the respiratory system. Cough and dyspnea may be present in a moderate picture of the disease, which can be classified as severe if the patient has fever and is associated with severe dyspnea, respiratory distress, tachypnea, and hypoxia. However, with the evolution of the disease and its sequelae, it was observed that it was a multisystemic condition. Although the number of new cases of the disease has drastically reduced worldwide, more attention from health systems is now needed for patients who have progressed with persistent symptoms, as these can negatively impact quality of life (QoL) by changes physical capacity, musculoskeletal function and respiratory function. Objective: To build predictive models for physical function in COVID-19 survivors, using demographic and anthropometric data, clinical findings, lung function and muscle strength, and also to assess the QoL of patients with post-COVID-19 syndrome (PCS) at 3, 6, 9 and 12 months after the acute phase of the disease, in addition to verifying the possible association of QoL with physical function, muscle function and pulmonary function. Methods: In the first study, a cross-sectional analysis was performed where 201 patients with CPS underwent physical function assessment using the Post-COVID-19 Functional Status Scale (PCFS), general fatigue assessment using the Functional Assessment of Chronic Illness Therapy scale -Fatigue (FACIT-F), handgrip strength (HGS) and spirometry. In the second study, an observational and longitudinal analysis was performed evaluating 350 patients with PCS, where the participants underwent quarterly follow-up, at 3, 6, 9 and 12 months after hospital discharge, evaluating them using the Short Form-36 (SF-36) to identify the level of QOL, correlating it with muscle strength (HGS), general fatigue (FACIT-F), lung capacity (spirometry) and physical capacity (PCFS). Results: In the first study, the number of participants classified as 0 (none), 1 (negligible), 2 (mild), 3 (moderate) and 4 (severe) on the PCFS scale was 12%, 20%, 19%, 24% and 24%, respectively. PCFS was significantly correlated with the following variables: FACIT-F (r = -0.424, P < 0.001), HGS (r = -0.339, P < 0.001), previous hospitalization (r = 0.226, P = 0.001), body mass-BMI (r = 0.163, P = 0.021) and sex (r = -0.153, P = 0.030). The regression model with the highest regression coefficient (R = 0.559) included the following variables: age, sex, BMI, FACIT-F, HGS and previous hospitalization. In the second study, when monitoring the evolution of the 350 participants who were evaluated in the 3rd month (T1), 74.6% reported general fatigue, 61.4% reported dyspnea, 45.4% had cough. In the 6th month (T2), 31.7% of the participants remained with post-COVID symptoms. In comparisons between T1 and T2, there was a significant improvement in the results of FACIT-F, pulmonary function and several domains of the SF-36. In the 9th month (T3), 13.1% of the participants remained with SPC. In the comparisons between T2 and T3, there was a significant improvement only in the domain of social aspects of the SF-36. At month 12 (T4), 9.1% of participants remained with post-COVID symptoms. When the absolute deltas between T1, T2, T3 and T4 were evaluated, significant correlations of the SF-36 domains with physical function, muscle function and pulmonary function were observed. Conclusion: The worsening in muscle strength and fatigue capacity are associated with reduced physical capacity, and PCFS may be useful to monitor post-COVID patients and determine the best treatment to be given according to the characteristics of each patient. When observing the evolution over 12 months of these patients, a more significant improvement was observed in the first 6 months after hospital discharge, identifying a correction between the improvement of the general fatigue indexes with the improvement of the QoL of the patients in the first 6 months, as well as an improvement in physical capacity related to improved QoL in the 12 months after hospital discharge.