Participants had a mean age of 37.6 years, and 80.0% of the patients were under 50. Most patients were female (66.3%), 62.7% were married, and 85.4% lived with relatives; similar marital and living status ratios were also observed in recent studies outside Vietnam7–9. A study conducted by Margarida Rodrigues et al. showed a significant improvement in limb and respiratory muscle strength, cough suppression, fatigue, balance, exercise capacity, and the ability to perform activities of daily living after one month of rehabilitation10. The literature provides strong evidence that physical activity is essential for patients with long-term COVID-19. This study reports that 68% of patients (280 of 410) reported physical activity, 44.6% exercised frequently or more than five days per week, and 62.9% exercised for more than 30 minutes per day.
Respondents report that 69.8% had their third or fourth booster shot, similar to what was reported in Vietnam on June 20 by the Ministry of Health.11 This report describes that the percentages of 1, 2, 3, and 4 COVID-19 mRNA vaccine doses among over 18-year-olds were 100%, 100%, 64.5% and 11.5%, respectively. After initial repeat coronavirus infections, the proportion of reinfected patients was 10.5%. Reinfection with COVID-19 with a low percentage showing the efficiency of the COVID-19 vaccination campaign launched 5K messages (face mask, disinfection, distance, no gathering, and health declaration) and citizen compliance with government recommendations.
In the study, the overall hospital admission rate of COVID-19 was 3.9%, which was also lower than that in other studies; this may be due to this study being conducted at different points in time and the effectiveness of COVID-19 prevention policies and control strategies in Vietnam to reduce the severity of illness and hospitalization.
The most common comorbidities were hypertension (36.8%), followed by respiratory diseases (24.2%), diabetes mellitus (21.1%), musculoskeletal disorders (14.7%), and cardiovascular diseases (10.5%). Meanwhile, the study conducted by Marwa Kamal et al. showed that most (83.3%) of the moderate-severe patients had comorbidities (type II diabetes, asthma, and hypertension)12.
In the present study, the most common symptoms of post-COVID-19 syndrome were fatigue (64.9%), followed by cough (57.1%), dyspnea (53.2%), and shortness of breath (52.9%). Our findings are also consistent with other studies showing that three typical symptoms of the post-COVID-19 condition include fatigue, dyspnea, and cough. Fatigue was the most frequent symptom in patients, but not all patients were the same, and there were differences between the data and studies12–15. In Sophie A M van Kessel’s study, fatigue was identified as the predominant or second most common symptom in individuals experiencing postacute COVID-19 and long-term COVID-19. Additionally, dyspnea frequently occurs.16
Most subjects suffered from cough (41.5%), fatigue (36.6%), dyspnea (32.7%), shortness of breath (29.5%), headache (13.4%) and palpitations (12.7%). With regard to questions on symptoms in patients at the clinic, the study sample showed cough in this domain of care (41.5%), followed by fatigue (36.6%), dyspnea (32.7%), shortness of breath (29.5%), headache (13.4%), and palpitations (12.7%). This symptom did not have a significant mortality advantage but did mean discomfort for some time (three to six months after recovery, up to 12 months). Typical symptoms usually include fatigue, dyspnea, cough, and shortness of breath, which significantly impact the daily activities and quality of life of post-COVID-19 patients. According to Goërtz et al.’s study, a significant number of patients continued to endure respiratory symptoms even after three months: Approximately 71% of patients reported experiencing shortness of breath, while 29% continued to have a persistent cough.17
The study revealed that 23.7% of all respondents identified depression as a score of ≥ 10 on the PHQ-9. In particular, of depressive patients, 80.4% of respondents reported mild, 16.5% moderate, and 3.1% severe. The difference in post-COVID-19 depression between studies is likely due to studies conducted over different times and differing criteria for the evaluation of long-term COVID-19 patients8,9,12. In addition, a study by Stephen X. Zhang et al. showed that the most commonly included depression instruments were used, with DASS-21 being the most popular (50%), along with the PHQ-9 (31.8%), for a total of 82,890 respondents.18 As in postacute COVID-19 patients, patients may experience a decline in psychological and cognitive functioning after a mean follow-up of 13 weeks.19
Factors influencing depression included age categories, religion, education degree, employment status, marital status, levels of family care, hospital admission due to COVID-19, chronic diseases, hypertension, and post-COVID-19 symptoms (shortness of breath, palpitations, fatigue, headache, abdominal pain, insomnia, brain fog, and loss of appetite). The most common symptoms in patients at the clinic include cough, dyspnea, shortness of breath, fatigue, and loss of appetite. Multivariable logistic regression analysis was performed to identify the factors related to depression, chronic diseases, and post-COVID-19 symptoms: palpitations and loss of appetite.