Trajectories of functional limitations, health-related quality of life and societal costs in individuals with long COVID: a population-based longitudinal cohort study

Abstract:

Objectives: To examine trajectories of functional limitations, fatigue, health-related quality of life (HRQL) and societal costs of patients referred to long COVID clinics.

Design: A population-based longitudinal cohort study using real-time user data.

Setting: 35 specialised long COVID clinics in the UK.

Participants: 4087 adults diagnosed with long COVID in primary or secondary care deemed suitable for rehabilitation and registered in the Living With Covid Recovery (LWCR) programme between 4 August 2020 and 5 August 2022.

Main outcome measures: Generalised linear mixed models were fitted to estimate trajectories of functional limitations, using the Work and Social Adjustment Scale (WSAS); scores of ≥20 indicate moderately severe limitations. Other outcomes included fatigue using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) reversed score (scores of ≥22 indicate impairment), HRQL using the EQ-5D-5L, and long COVID-related societal costs, encompassing healthcare costs and productivity losses.

Results: The mean WSAS score at 6 months after registration in the LWCR was 19.1 (95% CI 18.6, 19.6), with 46% of the participants (95% CI 40.3%, 52.4%) reporting a WSAS score above 20 (moderately severe or worse impairment). The mean change in the WSAS score over the 6-month period was -0.86 (95% CI -1.32, -0.41). The mean reversed FACIT-F score at 6 months was 29.1 (95% CI 22.7, 35.5) compared with 32.0 (95% CI 31.7, 32.3) at baseline. The mean EQ-5D-5L score remained relatively constant between baseline (0.63, 95% CI 0.62, 0.64) and 6 months (0.64, 95% CI 0.59, 0.69). The monthly societal cost per patient related to long COVID at 6 months was £931, mostly driven by the costs associated with working days lost.

Conclusions: Individuals referred to long COVID clinics in the UK reported small improvements in functional limitations, fatigue, HRQL and ability to work within 6 months of registering in the LWCR programme.

Source: Wang J, Goodfellow H, Walker S, Blandford A, Pfeffer P, Hurst JR, Sunkersing D, Bradbury K, Robson C, Henley W, Gomes M. Trajectories of functional limitations, health-related quality of life and societal costs in individuals with long COVID: a population-based longitudinal cohort study. BMJ Open. 2024 Nov 13;14(11):e088538. doi: 10.1136/bmjopen-2024-088538. PMID: 39537389. https://bmjopen.bmj.com/content/14/11/e088538 (Full text)

How Long is Long COVID? Evaluation of Long-Term Health Status in Individuals Discharged from a Specialist Community Long COVID Service

Abstract:

Background: Post COVID-19 syndrome or Long Covid (LC) is a novel fluctuating condition with a protracted course in some patients. Specialist LC services have been operational in the UK since 2020 and deal with a high caseload of patients. Aims: To evaluate long-term outcomes in patients discharged from a community-based LC specialist service.

Methods: A service evaluation study that included patients who were well engaged in the services [completed the standard Patient Reported Outcome Measures (PROMs) and received intervention from clinician(s)] and had been discharged for at least 3 months from the service. They consented to the study and completed standard PROMs: COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), EQ-5D-5L, and National Institute for Health and Care Excellence (NICE) criteria for Myalgia Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS).

Results: Out of 460 patients contacted, 112 (average of 37.6 months since infection and 9.8 months post-discharge) completed the PROMs. 90.2% patients continued to experience LC symptoms and disability and had not returned to their pre-COVID health status. The average EQ-5D-5L index score was 0.53 (SD 0.29) highlighting a significant disability and that LC had become a long-term condition (LTC) in majority of patients who responded to the survey. 43% patients met the criteria for suspected ME/CFS.

Conclusion: A proportion of LC patients develop Persistent Long Covid (PLC) consistent with a LTC and had a significant overlap with ME/CFS.

Source: Bodey, R.; Grimaldi, J.; Tait, H.; Godfrey, B.; Witton, S.; Sharda, J.; Tarrant, R.; Sivan, M. How Long is Long COVID? Evaluation of Long-Term Health Status in Individuals Discharged from a Specialist Community Long COVID Service. Preprints 2024, 2024090813. https://doi.org/10.20944/preprints202409.0813.v1 https://www.preprints.org/manuscript/202409.0813/v1 (Full text available as PDF file)

Long-COVID autonomic syndrome in working age and work ability impairment

Abstract:

Long-COVID19 has been recently associated with long-sick leave and unemployment. The autonomic nervous system functioning may be also affected by SARS-CoV-2, leading to a chronic autonomic syndrome. This latter remains widely unrecognized in clinical practice. In the present study, we assessed the occurrence of Long-COVID19 Autonomic Syndrome in a group of active workers as well as the relationships between their autonomic dysfunction and work ability.

This prospective observational study was conducted during the 2nd wave of the pandemic in Italy. Forty-five patients (53.6 ± 8.4 years; 32 M) hospitalized for COVID19, were consecutively enrolled at the time of their hospital discharge (T0) and followed-up for 6 months. Autonomic symptoms and work ability were assessed by COMPASS31 and Work Ability Index questionnaires at T0, one (T1), three and six (T6) months after hospital discharge and compared to those retrospectively collected for a period preceding SARS-CoV-2 infection. Clinical examination and standing test were also performed at T1 and T6.

One in three working-age people developed a new autonomic syndrome that was still evident 6 months after the acute infection resolution. This was associated with a significant reduction in the work ability. Recognition of Long-COVID19 Autonomic Syndrome may promote early intervention to facilitate return to work and prevent unemployment.

Source: Rinaldi L, Rigo S, Pani M, Bisoglio A, Khalaf K, Minonzio M, Shiffer D, Romeo MA, Verzeletti P, Ciccarelli M, Bordoni MG, Stranges S, Riboli E, Furlan R, Barbic F. Long-COVID autonomic syndrome in working age and work ability impairment. Sci Rep. 2024 May 23;14(1):11835. doi: 10.1038/s41598-024-61455-y. PMID: 38782998; PMCID: PMC11116376. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11116376/ (Full text)

Long-Term Impairment of Working Ability in Subjects under 60 Years of Age Hospitalised for COVID-19 at 2 Years of Follow-Up: A Cross-Sectional Study

Abstract:

Background: Coronavirus disease 2019 (COVID-19) can lead to persistent and debilitating symptoms referred to as Post-Acute sequelae of SARS-CoV-2 infection (PASC) This broad symptomatology lasts for months after the acute infection and impacts physical and mental health and everyday functioning. In the present study, we aimed to evaluate the prevalence and predictors of long-term impairment of working ability in non-elderly people hospitalised for COVID-19.

Methods: This cross-sectional study involved 322 subjects hospitalised for COVID-19 from 1 March 2020 to 31 December 2022 in the University Hospital of Bari, Apulia, Italy, enrolled at the time of their hospital discharge and followed-up at a median of 731 days since hospitalization (IQR 466-884). Subjects reporting comparable working ability and those reporting impaired working ability were compared using the Mann-Whitney test (continuous data) and Fisher’s test or Chi-Square test (categorical data). Multivariable analysis of impaired working ability was performed using a logistic regression model.

Results: Among the 322 subjects who were interviewed, 184 reported comparable working ability (57.1%) and 134 reported impaired working ability (41.6%) compared to the pre-COVID-19 period. Multivariable analysis identified age at hospital admission (OR 1.02, 95% CI 0.99 to 1.04), female sex (OR 1.90, 95% CI 1.18 to 3.08), diabetes (OR 3.73, 95% CI 1.57 to 9.65), receiving oxygen during hospital stay (OR 1.76, 95% CI 1.01 to 3.06), and severe disease (OR 0.51, 95% CI 0.26 to 1.01) as independent predictors of long-term impaired working ability after being hospitalised for COVID-19.

Conclusions: Our findings suggest that PASC promotes conditions that could result in decreased working ability and unemployment. These results highlight the significant impact of this syndrome on public health and the global economy, and the need to develop clinical pathways and guidelines for long-term care with specific focus on working impairment.

Source: Frallonardo L, Ritacco AI, Amendolara A, Cassano D, Manco Cesari G, Lugli A, Cormio M, De Filippis M, Romita G, Guido G, Piccolomo L, Giliberti V, Cavallin F, Segala FV, Di Gennaro F, Saracino A. Long-Term Impairment of Working Ability in Subjects under 60 Years of Age Hospitalised for COVID-19 at 2 Years of Follow-Up: A Cross-Sectional Study. Viruses. 2024 Apr 26;16(5):688. doi: 10.3390/v16050688. PMID: 38793570; PMCID: PMC11125725. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11125725/ (Full text)

Repeated Hand Grip Strength is an Objective Marker for Disability and Severity of Key Symptoms in Post-COVID ME/CFS

Abstract:

Post-COVID Syndrome (PCS) refers to a diverse array of symptoms that persist beyond 3 months of the acute phase of a SARS-CoV-2 infection. The most frequent symptom is fatigue, which can manifest both mentally and physically. In this study, handgrip strength (HGS) parameters were determined as an objective measure of muscle fatigue and fatigability. HGS parameters were correlated with other frequent symptoms among 144 female PCS patients suffering from fatigue, exertional intolerance, and cognitive impairment.

Seventy-eight patients met the Canadian Consensus Criteria (CCC) for post-infectious myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The severity of disability and key symptoms were evaluated utilizing self-reported questionnaires.

Notably, patients diagnosed with ME/CFS exhibited a higher overall severity of symptoms, including lower physical function (p < 0.001), a greater degree of disability (p < 0.001), more severe fatigue (p < 0.001), post-exertional malaise (p < 0.001), and autonomic dysfunction (p = 0.004). While HGS was similarly impaired in both PCS and ME/CFS patients, the associations between HGS and the severity of symptoms and disability revealed striking differences.

We observed significant correlations of HGS parameters with physical function across all patients, but with the key symptoms PEM, fatigue, cognitive impairment, and autonomic dysfunction in ME/CFS patients only. This points to a common mechanism for these symptoms in the ME/CFS subtype, distinct from that in other types of PCS. Further HGS provides an objective marker of disease severity in ME/CFS.

Source: Anna Paffrath, Laura Kim, Claudia Kedor, Elisa Stein, Rebekka Rust, Helma Freitag, Uta Hoppmann, Leif G Hanitsch, Judith Bellmann-Strobl, Kirsten Wittke, Carmen Scheibenbogen, Franziska Sotzny. Repeated Hand Grip Strength is an Objective Marker for Disability and Severity of Key Symptoms in Post-COVID ME/CFS.
medRxiv 2024.01.25.24301776;  https://www.medrxiv.org/content/10.1101/2024.01.25.24301776v1 (Full text available as PDF file)

Long COVID Disability Burden in US Adults: YLDs and NIH Funding Relative to Other Conditions

Abstract:

Background Long COVID (LC) is novel, debilitating and likely chronic. Yet, scant data exist about its disability burden to guide scientific research and public health planning. We estimated Long COVID’s non-fatal disease burden in US adults and its FY2024 actual: burden-commensurate research funding from the National Institutes of Health (NIH) relative to other conditions, and biological sex.

Methods We present YLDs/100,000 for 70 NIH Research, Condition, and Disease Categories (RCDCs). Prevalence of disabling Long COVID was obtained from cross sectional surveys of representative samples of US adults, from September 2022 to August 2023. Disabling Long COVID was defined as incident symptoms persisting more than 3 months post-COVID, that significantly compromise daily activities. We calculated burden-commensurate funding for the top YLD conditions and for female vs. male dominant conditions.

Findings Disabling Long COVID was reported by 1.5% (n= 10,401) of n=757,580 respondents: Compared to the overall sample, those with disabling LC disproportionately identify as female (64.4% vs. 51.4%) and experiencing disability (80.8% vs. 52.9%) anxiety (57.5% vs. 23.8%) and depression (51.3% vs.18.5%). It ranked in the top 25% of YLDs at 320/100,000, between Alzheimer’s (279.4/100,000) and asthma (355.7/100,000) but received just 10% of its actual: YLD-commensurate funding. Only 5 conditions received less actual: burden: commensurate funding, including Myalgic Encephalitis/Chronic Fatigue Syndrome (<1%), another post-viral, female-dominant condition.

Interpretation LC has debilitated 3.8 million (weighted frequency) US adults. Research funding for it, like other female dominant conditions, lags behind its disability burden.

Research in Context Evidence before this study – We analyzed Long-COVID’s (LC) non-fatal disease burden in the US–represented by YLD (years lived with disability= prevalence x disability weight) — and National Institutes of Health (NIH) research 2024 funding relative to other conditions. We searched PubMed through 11/28/2023 for Long COVID prevalence (US), and Long COVID disability and disease burden (not US-specific). The keywords “years lived with disability” + “COVID” yielded n= 38 articles (11/29/23); but most referenced “disability-adjusted life years” (DALYs) in other countries. Similarly, “disease burden” + Long COVID yielded 23 papers, but no US YLD data. See Supplement 1 for meta-analyses, systematic reviews and US studies of Long COVID prevalence and impact.

We instead sourced YLD data from the US Census Bureau’s Household Pulse Survey (HPS) and the Institute for Health Metrics and Evaluation (IHME) /Global Burden of Disease (GBD) Long COVID Study Group. The HPS queries adults about Long COVID-related symptoms and their impact on daily activities. We applied the IHME/GBD’s estimated Long COVID disability weight of 0.21 and harmonized it with our LC case definition from the HPS data in consultation with IHME/GBD researchers. To harmonize IHME/GBD disability weights for non-LC diseases/conditions with the NIH’s terminology, we consulted with NIH staff. LC definition and measurement affects prevalence and burden estimates; our use of high-quality data sources and transparency in reporting how they were applied reduces the risk of biased assumptions.

Added value of this study- Long COVID is a chronic debilitating condition. While there is ample research on COVID’s acute illness and loss of life, there are no population-based data on its disability burden. We provide that data. To guide scientific research and public health planning, we report YLDs associated with disabling Long COVID (i.e., symptoms significantly limit activity), and; compare it to other conditions’ YLDs, NIH funding, and female-vs. male-dominance. It ranked in the top 25% of YLDs at 320/100,000, between Alzheimer’s (279.4/100,000) and asthma (355.7/100,000) but received just 10% of its YLD-commensurate funding. Only 5 conditions received less burden-commensurate funding; 3/5 were female-dominant, including Myalgic Encephalitis/Chronic Fatigue Syndrome (ME/CFS) at <1%, another post-viral condition that shares significant overlap with Long COVID. Overall, median funding/YLD was >= 5 times greater for male-vs. female-dominant conditions.

Implications of all the available evidence-Nearly 4 million US adults (weighted frequency) live with disabling Long COVID. They disproportionately identify as female and as having a disability, anxiety and depression. Yet NIH funding for diagnostic and treatment research for Long COVID hasn’t kept pace with its disability burden.

Source: Karen BonuckQi GaoSeth CongdonRyung Kim. Long COVID Disability Burden in US Adults: YLDs and NIH Funding Relative to Other Conditions.

Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey

Abstract:

Background: As a consequence of their occupation, doctors and other healthcare workers were at higher risk of contracting coronavirus disease 2019 (COVID-19), and more likely to experience severe disease compared to the general population. However, systematic information on post-acute COVID complications in doctors is very limited.

Aims: This study aimed to determine the symptoms, perceived determinants, health and occupational impact, and consequent needs relating to post-acute COVID complications in UK doctors.

Methods: An online cross-sectional survey was distributed to UK doctors self-identifying as having Long COVID or other post-acute COVID complications.

Results: Of 795 responses, 603 fulfilled the inclusion criteria of being a UK-based medical doctor experiencing one or more post-acute COVID complications. Twenty-eight per cent reported a lack of adequate Respiratory Protective Equipment at the time of contracting COVID-19. Eighteen per cent of eligible respondents reported that they had been unable to return to work since acquiring COVID.

Conclusions: Post-acute COVID (Long COVID) in UK doctors is a substantial burden for respondents to our questionnaire. The results indicated that insufficient respiratory protection could have contributed to occupational disease, with COVID-19 being contracted in the workplace, and resultant post-COVID complications. Although it may be too late to address the perceived determinants of inadequate protection for those already suffering with Long COVID, more investment is needed in rehabilitation and support of those afflicted.

Source: D Bland, R Evans, A Binesmael, S Wood, S P Qureshi, K Fearnley, A Small, W D Strain, R Agius, Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey, Occupational Medicine, 2023;, kqad120, https://doi.org/10.1093/occmed/kqad120 https://academic.oup.com/occmed/advance-article-abstract/doi/10.1093/occmed/kqad120/7468904?redirectedFrom=fulltext

“It was almost like it’s set up for people to fail” A qualitative analysis of experiences and unmet supportive needs of people with Long COVID

Abstract:

Background: Almost twenty percent of adults with COVID-19 develop Long COVID, leading to prolonged symptoms and disability. Understanding the supportive needs of people with Long COVID is vital to enacting effective models of care and policies.

Design/methods: This qualitative sub-study explored the experiences of people with Long COVID and their unmet needs. Participants enrolled in a larger study to evaluate the post-acute cardiovascular impacts of COVID-19 were invited to participate in subsequent in-depth interviews. Participants were enrolled purposively until saturation at 24 participants. Data were analyzed using thematic content analysis.

Results: Participants focused on adaptations to life with Long COVID and their unmet needs in different life spheres. Three domains, 1) occupational and financial; 2) healthcare-related; and 3) social and emotional support, emerged as areas affecting quality of life. Although participants were motivated to return to work for financial and personal reasons, Long COVID symptoms often resulted in the inability to perform tasks required by their existing jobs, and unemployment. Those who maintained employment through employer accommodations still needed additional support. Participants encountered diagnostic challenges, challenges in accessing specialty appointments, insurance loopholes, high healthcare costs, and medical skepticism. Existing social networks provided support for completing daily tasks; however, those with Long COVID typically turned to others with similar lived experiences for emotional support. Participants found government support programs inadequate and difficult to access in all three domains.

Discussion: We propose a five-pronged policy approach to support persons with Long COVID. These overarching recommendations are (1) improve public awareness of Long COVID; (2) improve clinical care quality and access; (3) implement additional school and workplace accommodations; (4) strengthen socioeconomic benefits and social services; and (5) improve research on Long COVID.

Source: McNabb, K.C., Bergman, A.J., Smith-Wright, R. et al. “It was almost like it’s set up for people to fail” A qualitative analysis of experiences and unmet supportive needs of people with Long COVID. BMC Public Health 23, 2131 (2023). https://doi.org/10.1186/s12889-023-17033-4 https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-023-17033-4 (Full text)

A National Evaluation of Outcomes in Long COVID Services using Digital PROM Data from the ELAROS Platform

Summary:

Key findings of this service evaluation study:
• Patient characteristics: A sample of 5,318 patients from 14 participating NHS LC sites were analysed. The sample had a female:male ratio of 2.1:1. The average age was 48.4 yrs, with 87% (of those whose ethnicity was recorded) of white ethnicity and 9% of Black or Asian ethnicity.
• Comorbidities: This sample of patients had a low prevalence of co-morbidities (7%) with a clear onset of new LC symptoms after their COVID-19 infection supporting the onset of a new condition in this cohort of previously healthy individuals.
• Duration of LC: The average duration of LC in this sample was 384 days (>12 months) at first assessment in an LC site, with symptoms still ongoing at presentation, with more than 90% of the sample being non-hospitalised patients.
• Digital platform: A total of 17,471 PROMs (C19-YRS and EQ-5D-5L) were completed by this sample of patients with at least 1,532 participants completing multiple assessments on the same PROM on the digital PROM platform. The completion of PROMs around the 3-month mark was low for both measures (11.7% for C19-YRS and 14.6% for EQ-5D-5L). The ones who completed PROMs both around the 3-month mark and the 6-month mark were 4.3% for C19-YRS and 5% for EQ-5D-5L. This limits the generalisability of the findings in this evaluation to all the LC population, but the findings remain valid for this cohort of individuals.
• New-onset disability: 3,395 patients who completed at least one C19-YRS questionnaire at first assessment showed significant new-onset symptom burden, functional disability, and deterioration of overall health since the COVID-19 infection.
• Comparison between LC and other chronic conditions: The cross-sectional EQ-5D-5L Index value of 3,438 patients suggests the burden and disability in LC are worse than that reported in the literature for Diabetes Mellitus, COPD, Heart Failure, and Multiple Sclerosis.
• 3-month follow-up: Among those who completed an initial C19-YRS assessment and another at 3 months, there was a statistically significant improvement in symptom burden, functional disability and overall health. Patients at 3 months however still had significant LC symptom
burden and disability compared to their pre-COVID-19 health status, i.e., their condition had improved, but they were far off from a complete recovery. Among those who completed EQ-5D- National Evaluation of Long COVID Service Outcomes using ELAROS Data (09 Oct 23) Page 3 of 31
5L, at first assessment and at 3 months, their EQ-5D-5L Index score did not show any statistically significant improvement, but the EQ-5D-5L VAS showed a statistically significant improvement.
• 6-month follow-up: Among those who completed measures at the first assessment, 3 months, and 6 months, C19-YRS and EQ-5D-5L VAS showed statistically significant improvement whereas EQ-5D-5L Index Value showed statistically significant deterioration. Patients at 6 months still had
significant LC symptom burden and disability compared to their pre-COVID-19 health status, i.e., their condition had improved but had not fully recovered. The follow-up changes in scores support the efficacy of interventions provided by LC services and suggest that continued specialist input is needed to manage these patients with persistent symptoms.
• C19-YRS (condition-specific measure) vs EQ-5D-5L (generic measure): The 3-month month follow-up changes in scores and responsiveness of PROMs highlight that C19-YRS is a more sensitive measure than EQ-5D-5L in this cohort of individuals with LC. This is in keeping with the literature recommending the use of condition-specific measures in addition to EQ-5D-5L.
• Vocational problems: 62% of this sample had their work role affected with them having to either be on sick leave, reduce hours, change roles, or quit roles. Only 21% were able to maintain their previous roles held prior to their COVID-19 infection. This is suggestive of considerable productivity loss and financial implications to the country.
• Fluctuating condition: In patients who completed multiple assessments, it was evident that LC is a fluctuant condition with no necessary linear trend of improvement or deterioration between the domains of symptom burden, functional disability, and overall health. This highlights the need to understand the triggers for the condition and invest in self-management and ongoing support from community healthcare services.
• Long-Term Condition: In most patients in this sample, LC has evidently become a Long-Term Condition (LTC) with fluctuations in their condition causing disability and significant deterioration of their overall health status seen even after 18 months of LC with no complete resolution or full recovery. There needs to be a national investment in managing this new LTC along with other LTCs.

Source: Dr Manoj Sivan, et al.  A National Evaluation of Outcomes in Long COVID Services using Digital PROM Data from the ELAROS Platform. National Evaluation of Long COVID Service Outcomes using ELAROS Data (09 Oct 23) https://locomotion.leeds.ac.uk/wp-content/uploads/sites/74/2023/10/National-Evaluation-of-LC-Service-Outcomes-using-ELAROS-Data-09-10-23.pdf (Full text)

Long-COVID and its Physical and Neurological Symptoms in Adults: A Systematic Review

Abstract:

This review was carried out with the objective to study patterns of neurological, psychological and other physical consequences of COVID-19 in the long term. The guidelines of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) had been followed; 22 articles, published during January 2020 to September 2021, were selected. Original research, review articles, editorial and viewpoints were included. Google Scholar, Medline, and PubMed were searched through 2020 till 2021.

Data collection in selected studies was performed mainly through the online survey, telephone survey, use of medical records, and patient interviews. This systematic review contains the studies conducted in the American, Asian and European countries. The major outcomes identified were the neurological, psychological, and other long-term chronic manifestations of COVID‐19.

This review demonstrates that long-COVID has started to bring a huge wave of patients, the count of them being millions now, who can enter a phase of disability due to neurological damages if not treated during the early course of illness. Though more disabling than lethal, long-COVID patients with a neurological deficit is expected to overburden the healthcare system globally which is already been struggling to handle acute COVID-19 patients in this once-in-a-lifetime pandemic.

Source: Abdul Mannan Baig, Sameera Rizvi, Shahla Pardhan, Joachim Gerlach, Tazeen Saeed Ali. Long-COVID and its Physical and Neurological Symptoms in Adults: A Systematic Review. Vol. 17 No. 04 (2023): Pakistan Journal of Medical & Health Sciences. https://pjmhsonline.com/index.php/pjmhs/article/view/4549/4498 (Full text)