Clinical, physical, and psychological outcomes among individuals with post COVID-19 syndrome with different functional status: a cross-sectional study

Introduction: post-COVID-19 syndrome or long COVID is a condition characterized by symptoms that persist after the disease’s infection. Objective: to compare clinical, physical, and psychological outcomes among individuals with post COVID-19 syndrome with different levels of functional status after hospitalization for COVID-19. Methods: an observational, analytical, cross-sectional and with a quantitative approach with 75 individuals with post COVID-19 syndrome after hospitalization. Individuals underwent assessment of pulmonary function, six-minute walk test (6MWT), 1-minute sit and stand test (STS1), hand grip strength (HGS) and one repetition maximum test (1RM), Hospital Anxiety and Depression Scale (HADS), Short-Form Healthy Survey (SF-36) and Post-COVID Functional Scale (PCFS). Individuals were separated according to PCFS into two groups: low (LFL) and high (HFL) functional limitation (PCFS 1-2 and PCFS 3-4, respectively). Data regarding anthropometric and clinical characteristics, hospitalization history, and occupational activity were also collected. Results: individuals post COVID-19 syndrome with HFL presented worse score in the SF-36 in the functional capacity (p=0,01); pain (p=0,01), social aspects (p=0,01) and these individuals had a higher need for ICU admission (p=0,03) and prolonged hospitalization stays (p=0,04) compared to those with LFL. Conclusion: individuals with post COVID-19 syndrome that reported HFL exhibit poorer quality of life concerning the domains of functional capacity, pain, and social aspects when compared to those with LFL. Additionally, HFL individuals had a higher need for ICU admission and prolonged hospitalization stays.


INTRODUCTION
COVID-19 syndrome leads to impairment of all components of the respiratory system, resulting in the dysfunction of muscles involved in breathing. (1)This can lead to a reduction in lung capacity and volumes, muscle weakness, decreased functional capacity and exercise performance, among others. (1,2)Due to the complexity of the disease and its negative impact on functional and health variables, survivors of the infection may persist with varying degrees of functional, social, and emotional impairment in the long term, which is known as Post-COVID-19 Syndrome. (2,3)ost-COVID-19 syndrome or long COVID is a condition characterized by symptoms that persist after the disease's infection and cannot be attributed to other causes or illnesses. (2,3)The post-COVID-19 syndrome tends to manifest within three months after infection, (4) ranging from mild to incapacitating symptoms that worsen over time. (5,6)Muscle weakness, (7,8,9) sarcopenia, (8,9,10) and musculoskeletal limitations (8,9) are among the main complaints after the disease's infection, affecting at least approximately 25 % of survivors.In this sense, the presence of sarcopenia risk could exacerbate COVID-19 severity and hospital readmissions. (9)Additionally, COVID-19 survivors may also develop psychological and emotional sequelae, including post-traumatic stress disorder, depression, and anxiety. (11,12)onsidering the impact of COVID-19 on individuals, it is necessary to assess the magnitude of these alterations for appropriate treatment.Regarding functionality, Klok et al. (13) developed the Post-COVID Functional Status Scale (PCFS), which is a self-administered scale divided into two parts.Based on the responses gathered through the PCFS, the extent of functional limitations post-infection can be classified, ranging from the no restrictive symptoms to severe limitations. (13)lthough PCFS has demonstrated an excellent interobserver reliability, (14) given the fact that functional limitation assessed by the PCFS is subjective, it remains unclear whether individuals with worse performance on the scale also exhibit worse clinical, physical, and functional outcomes objectively assessed.For this reason, the objective of the present study was to compare clinical, physical, and psychological outcomes among individuals with post COVID-19 syndrome after hospitalization with different levels of functional status using the PCFS.

MATERIAL AND METHODS Study Design and Population
This is an observational, analytical, cross-sectional and with a quantitative approach, following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). (15)he study included a non-probabilistic sample of inpatients admitted to any hospital in Londrina City, Brazil.The individuals included in the study were recruited through social media, radio, and television in the city of Londrina, Brazil.The announcement invited individuals older than 18 years, with any physical sequalae after hospitalization due to COVID-19, to participate in a physical and functional assessment at the Physiotherapy Outpatient Clinic of the University Hospital of the State University of Londrina, Brazil.Participants older than 18 years of age, hospitalized for at least 24 hours due to COVID-19, reported after hospitalization a post COVID-19 syndrome characterized by fatigue, weakness and/or dyspnea, and without previous physical Salud, Ciencia y Tecnología.2024; 4:802 2 therapy treatment prior to evaluation were included.Exclusion criteria comprised musculoskeletal limitations hindering test execution, unstable cardiovascular disease without medical supervision, severe exacerbations impeding the continuity of evaluations, and the participant's expressed desire to withdraw from the study.
Evaluations were conducted between September 2020 and June 2022 at the Physiotherapy Outpatient Clinic of the University Hospital of the State University of Londrina, Brazil.All individuals included in the study signed the Informed Consent Form.The study was approved by the Research Ethics Committee of the State University of Londrina (Approval number 4,327,528).The study also followed the principles of the Declaration of Helsinki.(16)   Individuals selected for the study were contacted via telephone or through direct visits to the Cardiorespiratory Physiotherapy Outpatient Clinic at the State University of Londrina, Brazil.Assessments were conducted over two days depending on the participant's availability, with no more than a one-week interval between assessments.In the first visit, participants completed an initial evaluation form, providing information on personal details, clinical history, presence of comorbidities, lifestyle habits, occupational activity, and details regarding their COVID-19 hospitalization.In the second visit, the following outcomes were evaluated: Post-COVID Functional Status: Post-COVID Functional Status Scale (PCFS) was assessed to measure the impact of COVID-19 on functionality, (13) using the Brazilian version available on the authors' official website (https:// osf.io/tgwe3).The PCFS is a self-administered scale divided into two parts.In the first part, consists of a flowchart in which the following are evaluated: to the need for assistance with activities of daily living (ADLs), changes in the performance of these activities, presence of symptoms such as dyspnea, pain, fatigue, muscle weakness, memory loss, anxiety, and depression.Results range from 0 to 4, where 0 indicates the absence of functional limitations; 1 indicates insignificant functional limitations; 2 indicates mild functional limitations; 3 indicates moderate functional limitations, and 4 indicates severe functional limitations in daily life due to COVID-19.In the second part, the individual must answer a Likert-type scale with five options on the impact of COVID-19 on his/her daily life due to pain, depression, or anxiety, where 0 indicates no limitation or symptoms, and 4 indicates severe limitations in daily life.The higher the rating, the greater the impact of COVID-19 on the individual's functional status.The value considered for the analyses was the highest obtained value from the two parts of the scale.Individuals with PCFS between 1 and 2 were categorized as Post-COVID-19 syndrome with low functional limitation (LFL), and those with PCFS between 3 and 4 as Post-COVID-19 syndrome with high functional limitation (HFL). (13)ulmonary Function: Pulmonary function assessment was conducted using spirometry, employing a digital portable spirometer (Spirobank® II Smart, MIR brand, Italy), according to the American Thoracic Society/ European Respiratory Society guidelines, (17) yielding values for forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the FEV1/FVC ratio.Reference values employed were those proposed for the Brazilian population by Pereira and colleagues.(18) Exercise Capacity: The 6-Minute Walk Test (6MWT) was conducted to assess exercise functional capacity, following the guidelines of the American Thoracic Society and European Respiratory Society.(19) In this test, participants were instructed to walk the greatest distance possible in a 30-meter corridor over a period of 6 minutes.Two tests were performed with a minimum interval of 30 minutes between them, and the greatest distance covered was utilized for analysis.Reference values employed were those established by Britto and coworkers.(20) Functional Status: Functional status was assessed through the 1-Minute Sit-to-Stand Test (STS1). STS protocol and reference values used were as described by Strassmann et al. (21) Individuals were instructed to sit and stand from a chair as many repetitions as possible without support for one minute.Two tests were conducted with a rest interval between each.The highest number of repetitions was considered in the analysis.
Muscular Strength: Muscular strength was assessed through the handgrip strength test (HGS) and the onerepetition maximum (1RM) test.HGS was conducted by measuring isometric contraction using a portable digital dynamometer (Jamar® Plus model, Patterson Medical brand, USA).The value obtained was from the dominant arm, with the patient seated, elbow flexed at 90 degrees, and forearm and wrist in a neutral position. (22)Reference values followed those described by Mathiowetz and colleagues. (23)Muscular strength was also evaluated through the 1RM test, following the guidelines of Brown and Weir. (24)Muscles assessed included biceps and triceps brachii, latissimus dorsi, major pectoral, and femoral quadriceps.
Quality of Life: The Short-Form Health Survey-36 (SF-36) was employed to assess the participants' quality of life. (25)The SF-36 is an easily comprehensible generic instrument for evaluating quality of life. (26)It comprises an 11-question, 36-item multidimensional questionnaire encompassing eight domains: functional capacity, physical aspects, pain, general health status, vitality, social aspects, emotional aspects, and mental health.Higher scores indicate a better state of health.Results were transformed into scores ranging from 0 to 100, where 0 indicates poorer performance and 100 represents better performance in the respective domain.
Emotional Factors: The presence of anxiety and depression symptoms was assessed by using the Hospital Anxiety and Depression Scale (HADS), (27) validated in the Portuguese language. (28)The scale comprises two parts, one for anxiety and another for depression.Each part consists of seven questions with four alternative choices.The score for each question ranges from 0 to 3 points, depending on the intensity of symptoms.Thus, total HADS score varies from 0 to 21 points for each part.Scores of 0 to 7 indicate the absence of depressive or anxious symptoms; 8 to 10 suggest a potential case of depression or anxiety, while 11 to 21 indicate a probable case of depression or anxiety.

Statistical Analysis
Data normality distribution of numerical variables was assessed using the Shapiro-Wilk test.Results were presented as mean and standard deviation whether the variable exhibited a normal distribution; and median and interquartile range (25-75 %) if not.Categorical variables were expressed through absolute and relative frequencies.For comparison analysis, individuals were divided into two groups based on their functional level according to PCFS scores: PCFS 1-2, indicating LFL, and PCFS 3-4, indicating HFL.The unpaired Student's t-test or Mann-Whitney test and chi-square test was applied for continuous and categorical variables, respectively.The adopted statistical significance level was p<0,05.Statistical analysis was conducted using the SPSS version 22 (IBM SPSS Statistics, Chicago, Illinois, USA).This study included 75 individuals with post-COVID-19 syndrome after hospitalization discharge with different functional limitations.Thirty participants were classified as LFL (PCFS 1-2) and 45 as HFL (PCFS 3-4).Time between hospital discharge and the assessment was 36 [15-81] days.Sociodemographic and anthropometric characteristics, occupational status, comorbidities, and hospitalization history according to the PCFS score are shown in Table 1.Individuals with post-COVID-19 syndrome with HFL were significantly more prone to be admitted in ICU and presented a significantly higher median number of ICU days than those with LFL (Table 1).No differences were observed in clinical characteristics between groups.

Table 1 .
Sociodemographic and clinical characteristics of the participants. 76

Table 2 .
Exercise capacity, functional status, muscle strength, and emotional variables Abbreviations: % pred: percentage of the predicted value; 6MWT: Six-minute walk test; FEV1: forced expiratory volume in the first second; FVC: forced vital capacity; HADS: Hospital Anxiety and Depression Scale; kg: kilograms; l/sec: liters per second; m: meter; n: absolute frequency; PCFS: Post-COVID Functional Status SF-36; SF-36: Short Form Health Survey; STS1: Sit to Stand one minute.The data were expressed as median and interquartile range [IQR], mean and standard deviation (±), or numbers and percentage (%).*The adopted significance level was p < 0,05.