Impact of Covid-19 on health-related quality of life of patients: A structured review

Introduction Coronavirus disease (Covid-19) has led to a global pandemic since its emergence in December 2019. The majority of research into Covid-19 has focused on transmission, and mortality and morbidity associated with the virus. However, less attention has been given to its impact on health-related quality of life (HRQoL) of patients with Covid-19. Methods We searched for original studies published between December 2019 and Jan 2021 in PubMed, Scopus and Medline databases using a specific search strategy. We also explored literature on websites of distinguished public health organisations and hand-searched reference lists of eligible studies. The studies were screened by two reviewers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flowchart using pre-determined eligibility criteria. Data were synthesised, analysed descriptively and reported in line with PRISMA guidelines. Results In total, 1276 studies were identified through the search strategy. Of these, 77 studies were selected for full-text reading after screening the studies. After reading full-text, 12 eligible studies were included in this review. The majority of the studies used a generic HRQoL assessment tool; five studies used SF-36, five studies used EQ-5D-5L, and three used pulmonary disease-specific HRQoL tools (two studies used two tools each). The impact of Covid-19 on HRQoL was found to be considerable in both Acute Covid and Long Covid patients. Higher impact on HRQoL was reported in Acute Covid, females, older ages, patients with more severe disease and patients from low-income countries. Conclusion The impact of Covid-19 on HRQoL of Acute and Long Covid patients is substantial. There was disproportional impact on patients by gender, age, severity of illness and study country. The long-term impact of Covid-19 is still in its initial stage. The findings of the review may be useful to researchers, policymakers, and clinicians caring for people following Covid-19 infection.

Introduction such as 'a stay-at-home order', is associated with greater health risks, financial worry, and loneliness [25,26].
To our knowledge, no review has been published to date assessing the impact of Covid-19 on the HRQoL of patients with Covid-19 (confirmed or suspected). Moreover, very little is known about the impact of Covid-19 on HRQoL of Acute Covid (�4 weeks from onset of symptoms) and Long Covid (>4 weeks from onset of symptoms) patients. Therefore, the aims of this review are to fill the knowledge gap by identifying and assessing the studies reporting on the impacts of COVID-19 on HRQoL of patients with Covid-19 (confirmed or suspected) and exploring the risk factors for reduced HRQoL of Covid-19 patients.

Methods
This is a rapid review and it has been reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [27]. This review addresses the following research questions:

Literature coverage and search strategies
We searched PubMed, Scopus and Medline using a combination of the following search terms (in Title/Abstract): Corona, Covid, SARS-CoV-2, "quality of life". An example of search strategy is presented below (for PubMed). Additional filters used in the search strategies were English language, and original articles published between December 2019 and 25 th Jan 2021. We excluded letters, correspondences, notes, case reports, case series, communications, conference reports, reviews and editorials.
In addition to searching databases, reference lists of eligible studies were reviewed to identify additional papers.

Eligibility criteria
We selected original studies using the eligibility criteria given in Table 1. We also used the PICO (Population, Intervention, Comparison and Outcome) framework. In this review, population (P) will be humans with all ages and sexes, and Covid-19 confirmed or suspected patients who were isolated, intervention (I) is not applicable in this review, comparators (C) will be Acute Covid (�4 weeks from onset of symptoms) and Long Covid (>4 weeks from onset of symptoms), and outcomes (O) will be HRQoL of Covid-19 on health-related quality of life of patients (measured in physical, psychological, emotional and social dimensions), which were measured by different generic and specific tools, such as EQ-5D, SF-36, SF-6D (derived from SF-36), HUI (Health Utility Index), SGRQ. In this review, Covid-19 'confirmed patients' are defined as those patients who are diagnosed with Covid-19 infection and confirmed by laboratory test (antigen or antibody). 'Suspected patients' are those patients with symptoms of Covid-19 who could not get confirmation because of a variety of reasons (e.g. unavailability of testing facilities, or unable to carry out the test), and who were self-isolated.

Study selection, data extraction, analysis and reporting
Studies in this review was selected by two reviewers (ANP and SZ) independently using eligibility criteria. Disagreement were discussed by third author (GLY) and resolved. Detailed study selection processes are presented in Fig 1. Data extraction was also done by two reviewers (ANP and SZ) using an Excel spreadsheet. The third author (GLY) checked the completeness of the data extraction and suggested additions where necessary. The form was piloted using three eligible papers and revised before use. The following information were extracted from the selected studies: first author and publication year, study title, study type (e.g. survey, observational or experimental studies), study country, sample size (male/female), age of patients (e.g. mean, median, range), Covid-19 confirmed or suspected cases, how data were collected, severity of the patients, hospitalised or non-hospitalised patients, tools used to assess the quality of life (e.g. SF-36, SF-6D, EQ-5D-5L, HUI, SGRQ), and the time point at which HRQoL data were collected (assessment time from the onset of symptoms). In addition, we extracted data on health-related HRQoL (mean, median, IQR, SD, percentage, frequencies, p values, etc.), and also statistically significant factors identified in the study as affecting HRQoL of patients due to Covid-19.
Based on literature, we categorised Covid-19 into 'Acute Covid' (AC) and 'Long Covid' (LC). Covid-19 is defined as 'Acute' when the symptoms last 'up to 4 weeks' from its onset [28], and it is defined as 'Long' if the symptoms last 'more than 4 weeks' [29,30]. For those studies which did not clearly report their assessment time from the onset of symptoms (e.g. one month after discharge), we estimated the assessment time considering average length of stay reported in that study. Factors affecting Covid-19 on HRQoL on both groups of patients (i.e. Acute and Long Covid) are also assessed.

Inclusion criteria Exclusion criteria
We conducted descriptive synthesis and analysis of the data in this review but did not perform meta-analysis because of the limited number of studies and heterogeneous nature of the data. The study outcomes of interest were the impact of Covid-19 on HRQoL of Acute Covid patients and Long Covid patients and factors affecting these outcomes. Data were extracted on mean or median values of all HRQoL variables (such as 'pain/discomfort', 'self-care') including respective standard deviation or 95% confidence interval, or interquartile range were reported, as it is important to know spectrum of HRQoL impacts. We estimated confidence intervals for studies in cases where this information was missing (e.g. Halpin et al. 2020), based on the included studies [31]. Where combined HRQoL scores of all patients were not given, separate index values of each group (e.g. male and female patients, ward and ICU patients) were calculated as the weighted mean (e.g. for study by Halpin et al. 2020) [32]. References were managed in EndNote and the report was prepared in line with PRISMA guidelines.

Results
Fig 1 shows a flow diagram showing a total of 1227 studies were identified from database searches (PubMed, Medline and Scopus) and 49 studies were obtained from the website search. After removing duplicates, we retained 1023 studies. After screening by title and abstract, we retrieved 77 studies for full-text reading. After assessing the full-text, only 12 studies met our inclusion criteria and were therefore included in this review (no eligible studies were obtained from reference lists). Summary of these studies are provided in Table 2. Out of these 12 studies, the majority (n = 11) were observational (e.g. cross-sectional surveys) and one was an experimental study. The majority of the studies (n = 10) used generic HRQoL assessment tool (five used SF-36, five EQ-5D-5L), and the rest used a pulmonary disease-specific HRQoL tool, i.e. SGRQ (St George's Respiratory Questionnaire) tool (2/12),Clinical COPD Questionnaire (CCQ) (1/12), and PROMIS tool (1/12) (2 out of the 12 studies used two HRQoL assessment tools i.e. SGRQ and EQ-5D-5L, and CCQ and EQ-5D-5L). Among 12 studies, nine studies included all confirmed Covid-19 cases, two studies included a mix of both confirmed and suspected cases and one study included all suspected cases. Likewise, nine out of 12 studies included hospitalised or previously hospitalised patients, two studies included non-hospitalised patients and one study included a mix of hospitalised and non-hospitalised patients. Three studies were conducted on Acute Covid patients (�4 weeks from onset of symptoms) and 11 studies covered Long Covid patients (10 studies 4-12 weeks; 1 study >12 weeks) (HRQoL was assessed in both Acute and Long Covid patients in two studies, therefore total is >12).

Health-related quality of life measured by SF-36
Five out of twelve studies used SF-36 tool to assess the HRQoL of patients affected by Covid-19 [13,23,33,34]. A 36-item Short-Form (SF-36) health survey is a generic instrument (which does not use a preference based approach) to assess the HRQoL, which is used in clinical practice and research, health policy and evaluations and general population surveys [39]. It assesses eight health concepts (score range from zero to 100, a score of zero is equivalent to maximum disability and a score of 100 is equivalent to no disability): physical functioning (PF), role physical (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role emotional (RE) and mental health (MH) [39,40]. The majority of the included studies were conducted in China (3/5) and studies were mainly observational (4/5). Only three studies provided HRQoL scores of Covid-19 patients (using SF-36) [13,33,34]; one study provided combined (i.e. average total of all dimensions) HRQoL score (62.1±18.8) [23] and another study provided proportion of patients with functional and emotional impairment [35]. Amongst the three studies that reported HRQoL scores, only one study assessed HRQoL during Acute stage (<4 weeks) and after Acute stage, i.e. Long Covid (>4 weeks) [34]. The overall mean HRQoL scores of Acute Covid patients was 60.3 [34] and Long Covid patients ranged from 60.4 [34] to 86.4 [13], with higher SF-36 score representing better health ( Table 3). The lowest HRQoL score (60.4) was among the elderly patients (aged over 65 years) and highest HRQoL score (86.4) was with the majority of younger patients (54%, 18-46 years) and all patients were without comorbidities.
In the Acute Covid, highest score was reported in bodily pain (63.5) and lowest score was reported in physical functioning (53.2). However, in Long Covid highest score was reported in different dimensions in different studies. For example, Chen et al. (2020) reported highest score on physical functioning (94.2) [33]and Guo et al. (2020) reported the highest score on role emotional (100%) [13]. Likewise, similar variations were found in the lowest score on different dimensions, meaning there were no pattern on the highest or lowest scores based on HRQoL dimensions (Table 3). In Long Covid, mean physical components scores (PCS) were slightly higher than mental components scores in general (Fig 2). It is not possible to compare SF-36 HRQoL scores by country because of heterogeneity in presenting results and all three studies were from one country (i.e. China) (other two studies reported outcomes differently, not suitable for comparison). Likewise, impact of Covid-19 on HRQoL using SF-36 was not reported by illness severity to compare with. Only two study provided HRQoL scores by gender [13,33] and overall mean scores were higher in male patients (81.2 to 87.9) than female patients (78.7 to 83.9) in both studies [13,33] (Table 3). According to a study on Acute Covid (�4 weeks) [23], HRQoL score was significantly lower in the people aged 60 years or older (regression coefficient (B), -3.60; 95%CI, -5.13, -2.08, p < 0.001), and with comorbidity (B, -2.81; 95%CI, -4.18, -1.45, p < 0.001). HRQoL score was significantly higher in men (B, 1.89; 95% CI, 0.82, 2.95, p = 0.001), in people with higher education attainment (B, 6.82; 95% CI, 4.85, 8.78, p < 0.001, in people with their own business (B, 2.25; 95% CI, 0.73, 3.77, p = 0.004), in people with middle or high social status (B, 4.62; 95% CI, 3.09, 6.15, p < 0.001), in people who did not drink (B, 1.74; 95% CI, 0.61, 2.87, p = 0.003), and in those who did more physical activity (B, 2.72; 95% CI, 1.52, 3.92, p < 0.001) [23].
A study about Long Covid (> 4 weeks) reported that factor affecting HRQoL score was positive nucleic acid duration (longer duration had lower RE) was a factor affecting RE negatively (p = 0.01) [13]. Likewise, VT and MH scores were significantly affected by positive nucleic acid duration (longer than 14 days, p = 0.0311) and age group (age 46-69 years, p = 0.0472) [13]. Another study [33] showed that age was negatively associated with PF, RP (p<0.05), as reported above. PF, BP, and RE were negatively associated with the female sex (p< 0.05). Length of stay (LOS) was negatively associated with RE and RP.

Health-related quality of life measured by EQ-5D-5L
Five out of twelve studies used EQ-5D-5L tool to assess the HRQoL of patients with Covid-19 in this review [17,18,32,36,37]. EQ-5D-5L is a generic and preference based HRQoL instrument for describing and valuing health and higher index value represents a better health. It is based on a descriptive system that defines health in terms of five dimensions: Mobility, Self-Care, Usual Activities, Pain/Discomfort, and Anxiety/Depression [41]. A single utility score can be generated from the five dimensions questionnaire based on published tariffs with value 0 for death and 1 for perfect health. Negative value indicates life worse than death [41,42]. All five reviewed studies were observational, focused on Long Covid (>4 weeks) and conducted in Belgium, Germany, Iran, Norway and the United Kingdom. Mean HRQoL values in four studies (from Belgium, Iran, Norway, and the UK) were reported in a similar way, but the fifth study presented results in a different style [18]. The highest EQ-5D-5L index mean value was reported in the UK (0.714) [32], followed by Norway (0.690) [37], Belgium (0.620) [17] and lowest in Iran (0.612) [36] (Fig 3). The study in Iran covered all patients same as in the UK, but time of HRQoL assessment was roughly two to four weeks earlier in Iran (4-6weeks from onset of symptoms) than in the UK (6-10 weeks from onset of symptoms). It can be confirmed that time of HRQoL assessment is not the sole factor affecting HRQoL score because the study in Belgium [17] reported lower score than in the UK and Norway although it was assessed two to four weeks later (10-12 weeks after the onset of symptoms) than those studies covering similar patients in the UK and Norway (Fig 3).
A study about Long Covid (> 4weeks) in Iran [36] reported that the EQ-5D-5L index score was significantly different (in univariate analysis) by gender (p = 0.002) (males had higher score), age (p = 0.005) (higher in age � 40 years), educational status (p<0.001) (higher in patients with higher educational status), employment status (p < 0.001) (higher in patients with employment), and workplace status (p = 0.002) (higher in uncrowded workplace). Among the clinical factors (from univariate analysis), the mean EQ-5D-5L index score was   significantly lower if the patient had diabetes (p < 0.001), or heart failure (p = 0.002) or was admitted to hospital (p < 0.001) [36].

Health-related quality of life measured by SGRQ
There were two studies which assessed HRQoL of patients using St George's Respiratory Questionnaire (SGRQ) [10,18], which is pulmonary disease specific quality of life assessment tool. The score for each domain and the total score are ranged from 0 (no impairment/ no effect on quality of life) to 100 (maximum impairment/ maximum perceived distress). Thus, a higher score represents greater impairment or a poorer HRQoL. Both were observational studies and conducted in Italy and Germany. One of the studies compared HRQoL scores at two points of time: at the time of discharge from hospital and at 15 days of discharge [10]. Table 5 reports the SGRQ score on different dimensions among Acute Covid and Long Covid patients. The study in Italy by Santus et al. (2020) [10] reported that the SGRQ scores are significantly decreased (i.e. improved health) (p<0.01) in each dimension by time (comparing the assessment between around 2-3 weeks and 4-5 weeks, i.e. Acute Covid and Long Covid). The study also reported that 65% of patients achieved a clinically significant improvement in the SGRQ total score between hospital discharge and Day 15 [10]. However, while looking at the study conducted by Daher et al. (2020) in Germany [18] (Table 5), the patients

Health-related quality of life measured by CCQ
The Clinical COPD Questionnaire (CCQ) is a 10-item respiratory-specific quality of life assessment tool, which is divided into three domains: symptoms, mental state and functional state. The main outcomes are the CCQ total score (total scores of all domains divided by 10) and mean scores of the three separate domains. The scores are ranged from 0 to 6 points, with a higher value indicating lower quality of life [43]. The Clinical COPD Questionnaire (CCQ) tool was used by a study conducted in Belgium [17] for the Long Covid patients and reported the mean CCQ score as 2.01 points (± 0.98). According to the study, the symptoms and functional state domains were equally affected (2.13 ± 1.12 and 2.12 ± 1.22 points, respectively). The mental state domain was less affected compared to symptoms and functional state (1.56 ± 1.31) [17]. CCQ items 2 (Shortness of breath doing physical activities: 3.24±1.80) and 7 (Strenuous physical activities: 3.41±1.74) had the greatest impact on total scores, with 64% of the patients having shortness of breath during physical activities and 70% had problems during strenuous physical activities, respectively [17].

Health-related quality of life measured by PROMIS scale
PROMIS tool is used to identify symptoms and assesses the quality of life parameters [38]. This tool particularly assesses the general health, quality of life, physical health, mental health and social active role including fatigue, dyspnoea and muscular pain. A study in the USA [38] reported

Discussion
Main findings of the review are-the HRQoL score (i.e. SF-36 score) of patients with Acute Covid found to be lower compared to the patients with Long Covid. In Acute Covid, mental components score was slightly higher than physical components score (PCS) [34], but opposite was found in Long Covid [13,33]. The HRQoL scores of elderly patients were not considerably improved even after six weeks of discharge from hospitals [34]. The long-term impacts of Covid-19 is still in its initial stage and it has not been fully developed yet. Most of the available studies on impact of Covid-19 on HRQoL were conducted between 4 and 12 weeks from the onset of symptoms. There were some symptoms which were reported by patients with Long Covid found in our review include fatigue, muscular pain, shortness of breath and cough [35,38]. There were differences in the impact of Covid-19 on HRQoL of patients by study country, i.e. better HRQoL of the patients with Covid-19 from HICs compared to LMICs [32,36,37]. The common factors causing impact on both Acute and Long Covid were age, gender, severity of illness, comorbidity, income and educational level of the patients. As reported in the main findings above, overall HRQoL score of Acute Covid patients was lower (mean SF-36 score 60.3) compared to patients with Long Covid. However, HRQoL scores (using SF-36 tool) of Long Covid patients are still low and vary from 60.4 (lowest) to 86.4 (highest) [13]. The lowest HRQoL score in Long Covid patients in this review was mainly due to recruitment of only elderly Covid-19 patients group (aged >65 years) [34] unlike in other studies [13,33]. In addition, the HRQoL scores were not considerably improved among certain patient groups (e.g. elderly, ICU admitted patients) even after six weeks of discharge and lower in some domains even after three months of recovery (fatigue 69%, functional impairments in daily life 64%, and general quality of life 72%) [35]. In line with our findings, a study in Brazil among general population (age �7 years) reported that all dimensions of quality of life (using SF-36) significantly reduced during Covid-19 isolation than before isolation (p<0.05) [21].
All reviewed studies using EQ-5D-5L were on Long Covid (4 to 13 weeks from the onset of symptoms) and the mean EQ-5D-5L index values ranging from 0.61 to 0.71, which are considerably lower than outcomes of a similar study conducted with general population in China during the pandemic (0.949, SD 0.102) [44] and in Morocco (0.86) [45]. Lower magnitude of difficulties were reported among general population during Covid-19 pandemic in Vietnam [46] than found in our review [18]. Using SGRQ tool, studies found that there were considerable negative effects on patients' HRQoL mean score, ranging from 17.3 (SD: 15.9) to 35.7 (SD: 24.2) in Acute Covid and 10.6 (SD: 10.7) to 54 (IQR 19-78) in Long Covid for different dimensions of SGRQ. Higher SGRQ score (means lower HRQoL) in Long Covid in this review was mainly found in the study in Germany [18] because they included only severe patients in their study. Unlike shown by SF-36 and EQ-5D-5L, a study using SGRQ by Santus et al. (2020) showed significant improvement in HRQoL of patients even after two weeks of discharge (i.e. Acute Covid vs Long Covid) [10]. This may be because they included only those patients who were clinically stable and able to fill the questionnaire [10].
A study on Long Covid included in our review (Jacobs et al., 2020, USA) reported that 72.7% patients (95% CI: 65.6, 78.9) had persistent symptoms at day 35 after discharge and majority experienced fatigue (55%), muscular pain (50.6%), shortness of breath (45.3%) and cough (41.8%) [38]. These are similar to the findings reported in other studies [17,32]. Although there were studies conducted on the impact of Long Covid on HRQoL (conducted between 4 and 13 weeks from onset of symptoms), longer-term effects of Covid-19 (beyond 13 weeks) has not been fully developed yet [9]. A report published by WHO discussed about possible long-term impact of corona virus [8]. They reported that people recover from the illness after two to six weeks. However, some symptoms may linger or recur for weeks or months. Some patients may develop medical complications that may have lasting health effects. There may be prolonged illness due to the virus in young adults and children without underlying chronic medical conditions. More research needed to understand the long-term effects of coronavirus, why symptoms persist or recur, how these health problems affect patients and the clinical course and likelihood of full recovery.
While comparing the HRQoL by study countries, the highest EQ-5D-5L index value was reported in the high income countries (HICs), like UK (0.714) [32] and Norway (0.690) [37], and lowest in the low-and middle-income country (LMIC), Iran (0.612) [36]. The higher HRQoL of Covid-19 patients in high income countries like in the United Kingdom and Norway may be due to better health services of the countries rather than other factors [47,48] compared to LMIC, such as Iran. We confirmed from the study level investigation that patients' characteristics were not the causal factors for better health of the patients from the UK and Norway and worse HRQoL from the patients of Iran. For example, mean age of patients in the study of Iran was 58.4 (SD 18.2) and 18% of these patients were admitted in ICU. In the study in the UK, median age of the patients were 70.5 (range 18-93) and 32% of the patients were admitted in ICU. This means, the lower HRQoL of patients in Iran was not due to patients' characteristics, such as elderly patients or severity of illness.
The review also explored the factors affecting Acute Covid (�4 weeks from onset of symptoms) from different studies. HRQoL score (using SF-36) was significantly different by age of patients (lower in the patients aged 60 years or older, p< 0.001) and comorbidity (patients with comorbidity, p< 0.001) [23]. This is similar to the finding reported in a study from Canada [49]. In addition, HRQoL score was significantly different by gender (higher in male patients, p = 0.001), educational status (higher in patients with higher education attainment, p<0.001), business status (in people with their own business, p = 0.004), ability to pay for medication (higher score with better ability to pay, p <0.001), social class (in people with middle or high social status, p<0.001), alcohol use (in people who did not drink, p = 0.003), and physical exercise (in those who did more physical activity, p<0.001) [23].
This review found that HRQoL of Long Covid patients (>4 weeks of onset of symptoms) admitted in ICU (severely ill patients) were worse EQ-5D-5L scores ranging from 0.581 to 0.693) than patients admitted in normal ward (moderately ill patients) (scores ranging from 0.613 to 0.724) [32,36,37]. This finding is intuitive as severity of illness impact on physical health, mental health and well-being of people and thus reduces quality of life [50]. Moreover, this review found HRQoL scores in male patients (SF-36 scores from 81.2 to 87.9) were higher than female patients (scores from 78.7 to 83.9) [13,33] (while keeping other factors constant). These findings are also supported by other similar study [36]. The impact of Covid-19 was found worse in older patients (�60 yrs: 0.554) than younger patients (�40 yrs: 0.618). A study in the USA also supported above findings [38]. A study among general population during Covid-19 pandemic also reported that people with aging had lower HRQoL scores than younger population [44]. In addition, a study about Long Covid (> 4 weeks) (using SF-36) reported that factor affecting HRQoL score was positive nucleic acid duration (longer duration had lower RE) (p = 0.01) [13]. Length of stay (LOS) was negatively associated with RE and RP. Logistic regression analysis showed that being overweight (p<0.05) or obese (p<0.05) were significant factors linked with a poor physical component summary (PCS) [33]. These findings were also supported by a study in Morocco and Vietnam [45,46].
Majority of the included studies covered impact of Covid-19 on hospitalised or previously hospitalised patients. There were lack of studies covering non-hospitalised patients with Covid-19. Likewise, most of the studies (10 out of 12, 2 studies covered both-both Acute and Long Covid) assessed the impact of Covid-19 on HRQoL between four weeks and 12 weeks from the onset of symptoms. There were lack of HRQoL studies conducted on Acute Covid patients within 4 weeks from onset of symptoms and on Long Covid patients after 12 weeks from onset of symptoms. Similarly, there were no studies, which assessed impact of Covid-19 on patients under 18 years of age. As we discussed in the results section, impact of Covid-19 on HRQoL of patients were mainly measured using generic instruments, such as SF-36 and EQ-5D, and none of the studies have reported its preference-based counterpart SF-6D. Disease-specific HRQoL assessment tools were also used but less frequently than generic tools (SGRQ was used by two studies [10,18], CCQ and PROMIS were used by one each [17,38]). Likewise, they used different calculation methods and presentation styles even in the studies using similar tool. These issues not only make difficulties in comparison of impact of Covid-19 on HRQoL of patients with Covid-19 between studies, but also confuses policy makers about the use of research findings for policy interventions.
Strengths of the review include-it is a first review of its type to date, as there were no published review on this topic was found. Likewise, studies for this review were searched in multiple databases (PuBMed, Scopus and Medlines), websites of distinguished organisations and reference lists. We used robust selection criteria and the study was reported according PRISMA guidelines. Likewise, we included all eligible studies from all over the world without limiting geographical boundaries. Moreover, we compared the review findings by country, gender, age group, and severity of patients, using wide range of relevant literature published till date.
There are some limitations in this rapid review. First, we included the original articles published in English language only. Second, we included studies published online. There may be other unpublished studies about the impact of Covid-19 on HRQoL of confirmed or suspected patients. Third, we included only those articles which assessed HRQOL of patients with Covid-19 (confirmed or suspected) and excluded other HRQoL studies on general population or with other disease groups, because these were out of our study criteria. Fourth, we also included three papers with clinically suspected Covid-19 patients [23] and both confirmed and suspected patients [17,35] in this review, as during the start of the Covid-19 pandemic, testing facilities were not widely available and researchers had to include suspected Covid-19 patients as well in their research studies. Therefore, we included these studies in our review according to our inclusion criteria. However, these papers might be slightly impacted the outcomes of the review results. Fifth, we did not assess the quality of the included papers in this review; however, we ensured that the study had required information on important variables of interest (i.e. quality of life scores, types of patients included in the study).

Conclusions
We concluded that there were higher impact of Covid-19 on HRQoL of Acute Covid (confirmed or suspected) patients compared to Long Covid patients. However the impact was affected by many other factors, such as age, comorbidity, severity of illness of patients and the impact is not reduced considerably as time goes by (i.e. even after two months) [17]. In addition, HRQoL of patients with Covid-19 was considerably lower than the general population during the pandemic. This review also concluded that the impact of Covid-19 on HRQoL of patients from LMICs were considerably lower than the patients from high-income countries (HICs), such as the UK and Norway. Similarly, the HRQoL scores (both physical health and mental health components) were considerably lower among the severe patients who were admitted in ICU compared to moderate patients who were admitted in general wards; the HRQoL scores were found to be lower in female Covid-19 patients, and patients who were in old age (age >60 yrs). Although the long-term impact of Covid-19 is not fully developed, there is a consensus in the included studies that Covid-19 causes long-term problems such as fatigue, cough and shortness of breath, which reduce HRQoL of Covid-19 patients at a considerable level. In addition, most of the factors affecting HRQoL found to be similar for both Acute Covid and Long Covid patients.
There is a need for more studies on Acute Covid (within 4 weeks from the onset of symptoms) and Long Covid after 12 weeks from the onset of symptoms, covering non-hospitalised patients and children and adolescents below 18 years of ag., using standard HRQoL tools (e.g. tools using preference based approach (e.g. EQ-5D, SF-6D) and disease specific tools CCQ, SGRQ) with standard method of calculating HRQoL and presenting estimates (i.e. mean scores for each dimension with SD and 95% CI, median with range, or % of patients facing difficulties for each dimension).
The findings of the review may be useful to the researchers, policy makers, clinicians and those who are interested in the HRQoL of patients affected by Covid-19 pandemic.
Supporting information S1 Data. Data file related to the paper. (XLSX)