Abstract
The COVID-19 pandemic in December 2019 has severely affected the lives of people around the world. Studies on the health-related quality of life (HRQoL) of long-COVID are few in China. Therefore, this study aimed to investigate whether long COVID has an impact on HRQoL.
Persistent symptoms and low annual household income were associated with lower health utility values. Therefore, interventions should be designed and implemented to improve the quality of life of COVID-19 recovering patients, especially those with persistent symptoms and low-income patients who require a comprehensive evaluation.
The results contribute to the evidence for the impact of COVID-19 on the quality of life of recovered patients. The improvement of HRQoL in such patients is one of the ultimate goals of healthcare practices together with the need to provide the optimal long-term patient care.
Introduction
Since the start of the COVID-19 pandemic in December 2019, the disease has severely affected the lives of people around the world. 1 Acute coronavirus infection produces symptoms of acute respiratory infection as well as a variety of clinical syndromes, such as thrombosis, cardiac complications (including myocarditis) and neurological complications. 2 Although most patients recover fully from an acute coronavirus infection within a few weeks, some patients may experience persistent symptoms, which are called long COVID. 3 The National Institute for Health and Care Excellence (NICE) in the UK has defined long COVID as “signs and symptoms that develop during or following an infection consistent with COVID-19 and persist for more than 4 weeks and cannot be explained by an alternative diagnosis.” 4
Common symptoms in patients with long COVID include fatigue, cough, dyspnea, chest pain, headache, sleep disturbances, smell disturbances, and taste disturbances.5 -8 Lemhöfer et al 9 surveyed 1027 patients with mild to moderate SARS-CoV-2 infection in Germany, of whom 61.9% reported persistent symptoms for more than 3 months after infection. The top 5 most frequent persistent symptoms were fatigue/weakness (37.5%), pain (28.2%), dyspnea (26.0%), sleep disturbance (26.0%), and fear/anxiety (24.9%). Sigfrid et al 10 surveyed 327 hospitalized patients with new coronavirus infections in the UK; 93% of participants had persistent symptoms, of which fatigue (83%) was the most prevalent, followed by dyspnea (54%). The diversity and length of symptoms and the wide impact on the population may cause health hazards, to the extent of leading to a decline in health-related quality of life (HRQoL). 10 HRQoL 11 is a multidimensional concept that reflects a patient’s physical, psychological, social, and emotional health. It can be used to quantify mental and physical health so that healthcare workers can assess the impact of the disease and recognize areas of improvement to alleviate patient symptoms.
Tsuzuki et al 12 used the EuroQol-5 Dimension 3-Level (EQ-5D-3L) to measure HRQoL in 457 patients in April 2020. These patients were assessed at least 8 weeks after the COVID-19 infection. The study found that patients with long COVID had significantly lower EQ-5D-3L index values than patients without long COVID (0.85 vs 0.96). Malesevic et al 13 used 2 scales, the EuroQol-5 Dimension 5-Level (EQ-5D-5L) and MOS 36-item Short-Form Health Survey (SF-36) to assess 112 long-COVID patients who had been infected with COVID-19 for at least 3 months. The EQ-5D-5L scores showed that most patients reported limitations in performing daily activities with pain/discomfort and anxiety. The SF-36 revealed lower physical health scores in patients with long COVID compared to those of the general Swiss population prior to the COVID-19 pandemic (38.5 vs 50).
Studies on the HRQoL of long-COVID patients have been conducted in some countries but there are few relevant studies in China. There have been some studies14,15 in China on the long-term health effects of COVID-19 on patients discharged from hospitals. However, there are few studies on the long-term health effects and health utility values of long COVID in the general population. Therefore, this study aimed to investigate the symptoms and HRQoL of the general population with long COVID and whether long COVID impacts HRQoL.
Materials and Methods
Study Design and Population
This study was a cross-sectional survey, conducted from 1 February to 9 March 2023. Participants were recruited from Harbin Medical University, Heilongjiang Province, and the investigators surveyed students and their students’ families and friends amongst others. This study investigated the non-hospitalized acute COVID-19 population with an onset of >4 weeks according to the NICE definition 4 (“signs and symptoms that develop during or following an infection consistent with COVID-19 and persist for >4 weeks and cannot be explained by an alternative diagnosis”) of the time criterion for long COVID. These patients were diagnosed positive using RT-PCR nasal swab or antigen test. The population was subsequently categorized into long-COVID and non-long-COVID groups according to the presence or absence of persistent symptoms. Data was collected through a questionnaire. After the participants provided informed consent, the investigators explained the questionnaire and it was subsequently completed face-to-face on site, or telephonically if absent. The questionnaires were entered through EpiData 3.1.
Measures
The questionnaire was divided into 3 main sections: demographic characteristics, symptoms, and severity of long COVID, and HRQoL. Demographic characteristics included age, sex, place of residence, educational level, annual household income, marital status, health insurance, smoking, drinking, physical exercise, and chronic diseases.
Following the National Institutes of Health report 16 and some relevant studies17,18 on long COVID, the symptoms of long COVID that we listed in the questionnaire were fatigue, weakness, cough, memory loss, poor concentration, phlegm in the throat, shortness of breath/difficulty breathing, irregular menstruation, hair loss, drowsiness, chest pain/tightness, sleep disorders, headache, loss of taste or distorted sense of taste, loss of smell or distorted sense of smell, loss of appetite, runny/stuffy nose, myalgia, palpitations, diarrhea, tinnitus, nausea and vomiting, and night sweats. The severity of long COVID was measured as slight, mild, moderate, severe, or very severe.
The presence of chronic diseases and the severity of long-COVID symptoms were obtained by self-report. To ensure the credibility of the questionnaire, the investigators were trained postgraduates at medical colleges. At the time of the survey, the investigators conducted detailed counseling on chronic diseases, long-COVID symptoms and their severity to improve the accuracy of the respondents’ answers.
HRQoL was assessed using the EQ-5D-5L. 19 The EQ-5D-5L was developed by the EuroQol Group and is considered one of the best tools for measuring HRQoL. The EQ-5D-5L descriptive system comprises five dimensions—mobility, self-care, usual activities, pain/discomfort, and anxiety/depression—each of which has 5 levels (no problem, slight problem, moderate problem, severe problem, and unable to do). The Chinese version 20 of the EQ-5D-5L has been validated with satisfactory reliability and validity. The EQ-5D-5L has a corresponding Chinese utility point system that converts EQ-5D-5L values to health utility values. 21
Statistical Analysis
The sample size was calculated based on the following formula:
Frequencies and percentages were used to describe the categorical variables, including demographic characteristics, symptoms of long COVID, number of those with long COVID, and severity of long COVID. To decrease the bias introduced by differences in the characteristics (sex, age, place of residence, etc.) of the participants in the 2 groups (with and without long COVID), we used propensity score matching (PSM) techniques. We then examined whether the matching procedure could balance the covariates in the long-COVID group and non-long-COVID group using the chi-square test. After PSM, the
Results
Characteristics of Participants
In this study, 314 patients were investigated, and 7 invalid questionnaires excluded, resulting in a questionnaire validity rate of 97.78%. Of the 307 participants included in the final analysis, 124 (40.39%) had long COVID, whereas 183 (59.61%) did not. 213 (69.38%) were women. Approximately three-quarters of participants were <30 years old (73.62%), 75.24% lived in a town or city, 69.71% were unmarried, and 73.62% engaged in some form of exercise. Over 40% of the participants had received education at the level of college/university (43.97%) and 41.37% had an annual household income of 80 000 to 150 000 yuan. Nearly two-thirds of participants paid for basic medical insurance for urban and rural residents (57.33%), 89.90% were non-smokers, and 48.21% were non-drinkers, 14.66% were suffering from chronic diseases. There was a significant difference in the “age,” “marital status,” “health insurance,” “physical exercise,” and “chronic disease” covariates between 2 groups (
Characteristics of Participants.
UEBMI = basic medical insurance for urban employee; URBMI = basic medical insurance for urban and rural residents.
Type, Severity, and Number of Long COVID Symptoms
Overall, 22 symptoms were reported by the participants. The most common symptoms of long COVID were fatigue/weakness (83 [27.04%]), with 5 (6.02%) people reporting a low impact, 64 (77.11%) reporting a mild impact, and 14 (16.87%) reporting a moderate impact. This was followed by coughing (42 [13.68%]), memory decline (21 [6.84%]), poor concentration (20 [6.51%]), phlegm in throat (16 [5.21%]), shortness of breath/difficulty breathing (16 [5.21%]), irregular menstruation (16 [5.21%]), hair loss, drowsiness (14 [4.56%]), and chest pain/tightness (14 [4.56%]). Most patients with long COVID reported mild effects from their symptoms. None reported severe impacts (Figure 1).

Distribution of symptoms of long COVID.
Of the 307 participants, 36 (11.73%) reported 1 symptom, 31 (10.10%) reported 2 symptoms, 19 (6.19%) reported 3 symptoms, and 38 (12.38%) reported 4 symptoms (Table 2). After PSM, 86.29% (107) of the 124 participants with long COVID were included in the long-COVID group, and 89.07% (163) of the 183 participants without long COVID were included in the non-long-COVID group. There were no statistically significant differences in any of the demographic characteristics (
Numbers of Symptoms of Long-COVID.
Characteristics of Participants After Propensity Score Matching.
Comparison of Index Values of EQ-5D-5L Across Participant Demographics
The EQ-5D index scores did not follow a normal distribution after propensity matching when comparing the long-COVID and non-long-COVID groups. In this study, the Mann-Whitney
The Index Values of the EQ-5D-5L Across Participants.
Multivariable Regression Analysis
Annual household income and long COVID were significant factors influencing the health utility value (P < .05). The presence of long COVID negatively affected health utility. Compared with participants without long COVID, participants with long COVID had a lower health utility value by 0.225. Furthermore, an annual household income of 150 000 yuan or more had a positive effect on the health utility value. Participants with annual incomes greater than 150 000 yuan had a 0.164 higher health utility value than those with annual incomes less than 80 000 yuan. No other variables were associated with health utility value (Table 5).
Multivariable Regression Analysis for Factors Associated With the Index Values of EQ-5D-5L Among Participants (N = 270).
CI = confidence interval; ref = reference category.
Comparison of the Two Groups Under Different Dimensions of the EQ-5D-5L
The symptom with the highest percentage reported by patients was anxiety/depression (29.63%), followed by pain/discomfort (18.52%). Approximately 5.93% participants had mobility problems, and 5.19% had problems with their usual activities. The self-care dimension had the lowest rate, with 2.22% of respondents reporting problems at any level. There were no significant differences in mobility, self-care, or usual activities between those with and without long COVID across the 5 EQ-5D-5L dimensions. However, assessments of pain/discomfort and anxiety/depression in the group with long COVID showed that more individuals in that group were affected by these related symptoms than in the group without long COVID (
Distribution and Comparison of the Proportion of Patients Reporting EQ-5D-5L Domain Impairment.
Discussion
Current research on long COVID focuses more on the hospitalized population than the general population. Few studies have measured health utility values in the general population with long-COVID in China. This study focused on long-COVID symptoms, symptom severity, and HRQoL of the general population after acute COVID-19 infection in China. The major findings of this study indicate that people with long COVID exhibit lower HRQoL.
In our study it was found that 40.39% of the respondents exhibited at least 1 persistent symptom after recovery from acute COVID-19 infection. This percentage is higher than that reported by Perlis et al 23 (14.8%). The reasons for this variation may be due to differences in time to recovery from acute COVID-19 infection at time of investigation. The persistent symptoms of COVID-19 tend to improve over time. 24 The Perlis study took place 6 months after recovery from acute COVID-19 infection, whereas this study took place 1 to 2 months after recovery. In our study, the most common symptoms of long COVID were fatigue/weakness, cough, memory decline, poor concentration, and phlegm in the throat. These findings are consistent with those of previous studies,3,25 in which fatigue was the most common long-COVID symptom, as well as the figures from the UK Office for National Statistics. 26
Regarding the severity of long-term long-COVID symptoms, all participants indicated that their symptoms were of moderate or lower severity, with no symptoms above severe. This may be explained by the fact that 73.62% of the respondents were under 30 years of age. Some studies have shown that older adults have more severe long-COVID symptoms owing to the presence of underlying medical conditions and lower levels of physical activity.27,28
The study shows that, there was a higher proportion of older patients (56.79%) with long-COVID, consistent with the results of 1 study. 29 This may 30 be owing to older individuals being more susceptible to long-COVID because of their declining physical abilities. The presence of chronic disease was associated with having long COVID. Some studies31,32 have similarly shown that chronic kidney disease, hypertension and diabetes are risk factors for developing long-COVID. Compared to non-exercisers, those who are exercising have a lower prevalence of long COVID (35.40%), and the recent data from US college athletes show 33 a much lower prevalence of long-term symptoms. Therefore, we should focus on priority groups and adopt preventive measures at the early stages of the disease for older individuals and those who have chronic diseases. Individuals who already have long-COVID can seek care from a healthcare provider to develop a personal healthcare management plan to help improve their symptoms. Furthermore, it is important to encourage individuals to exercise.
COVID-19 has long-term effects on patients, not only in terms of symptoms but also HRQoL.
34
To compare the differences in HRQoL between patients with and without long COVID, we adopted PSM for the relevant demographic variables to ensure homogeneity between the 2 populations. The results of the study showed that after PSM, the health utility value of 0.94 for the long-COVID group was lower than the health utility value of 0.97 for the non-long-COVID group (
The results of the multiple linear regression showed that those with long-COVID symptoms exhibited lower health utility values. Moreover, participants with annual household incomes of more than 150 000 yuan had significantly higher health utility values than those with annual household incomes of less than 80 000 yuan, which may be attributed to better access to healthcare and preventive services in the higher-income group. 37
This study also analyzed the EQ-5D-5L for each dimension, and the proportions of people with problems with pain (33.64% vs 8.59%) and anxiety (39.25% vs 23.31%) were significantly higher in the long-COVID group than in the non-long-COVID group. Huynh et al 38 obtained the same result as this study. Pain is a common symptom following acute COVID-19, having a negative impact on HRQoL and increasing the incidence of anxiety. 39 There may be several reasons for this anxiety. First, the patient may be unwell due to the presence of symptoms and be overly worried about their health. Second, there may be a fear that the symptoms will worsen and last for an unpredictable period. Third, the patient’s work, life, and studies may face a brief period of stagnation owing to the presence of the symptoms. The coupling of pain and anxiety ultimately leads to a reduction in HRQoL. Therefore, pain and mental health should be important concerns, and it is important to provide the necessary care and psychological counseling to patients with long COVID with a view to improving their HRQoL.
There are some limitations to our study. First, the study was not randomized for the long-COVID and non-long-COVID groups, and the 2 populations were poorly comparable. However, the study did use PSM to eliminate the effect of confounding sociodemographic variables on the results for the 2 populations. Second, the sample size is not large enough so that prevalence was compromised. Third, the severity of long-COVID symptoms and prevalence of chronic diseases was self-reported, and lacks a certain degree of objectivity. However, to ensure the questionnaire’s credibility, the investigators were trained postgraduates at medical colleges. At the time of the survey, the investigators conducted detailed counseling on the severity of long-COVID symptoms to improve the accuracy of the individuals’ responses.
Conclusion
This study showed that 40.39% of respondents had long COVID symptoms after acute COVID-19 infection. Most patients with long COVID reported mild effects from their symptoms. The long-COVID group had lower health utility scores than the non-long-COVID group (0.94 vs 0.97). Persistent symptoms and low annual household income were associated with lower health utility values. Therefore, interventions should be designed and implemented to improve the quality of life of COVID-19 recovering patients, especially those with persistent symptoms and low-income patients who require a comprehensive evaluation.
Supplemental Material
sj-docx-1-inq-10.1177_00469580241246461 – Supplemental material for Impact of Long COVID on Health-Related Quality of Life Among Patients After Acute COVID-19 Infection: A Cross-Sectional Study
Supplemental material, sj-docx-1-inq-10.1177_00469580241246461 for Impact of Long COVID on Health-Related Quality of Life Among Patients After Acute COVID-19 Infection: A Cross-Sectional Study by Chengyao Sun, Ziwei Liu, Sixuan Li, Yuqi Wang and Guoxiang Liu in INQUIRY: The Journal of Health Care Organization, Provision, and Financing
Footnotes
Authors’ Contributions
Declaration of Conflicting Interests
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Supplemental Material
References
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