Participant Demographics and Baseline Characteristics (Table 1)
Table 1
Demographic Characteristics of COVID-19 Infected Individuals
variables | control(N = 98) | Post covid-19 conditions (N = 208) | p-value |
Gender N(%) | | | 0.230 |
Male | 59 (60.2%) | 110 (52.9%) | |
Female | 39 (39.8%) | 98 (47.1%) | |
Education N(%) | | | 0.609 |
Elementary school or below | 1 (1.0%) | 1 (0.5%) | |
Junior high school | 0 (0.0%) | 4 (1.9%) | |
High school or vocational school | 11 (11.2%) | 31 (14.9%) | |
College | 15 (15.3%) | 36 (17.3%) | |
Bachelor's degree | 54 (55.1%) | 111 (53.4%) | |
Graduate school or above | 16 (16.3%) | 24 (11.5%) | |
Primary source of household income N(%) | 60 (61.2%) | 110 (52.9%) | 0.383 |
Lifestyle | | | |
Smoking | 22 (22.4%) | 37 (17.8%) | 0.335 |
Alcohol drinking* | 51 (52.0%) | 74 (35.6%) | 0.006 |
Betel quid chewing + | 3 (3.1%) | 3 (1.4%) | 0.387 |
Age (Mean ± SD) | 41.0 ± 10.1 | 41.3 ± 10.4 | 0.862 |
BMI (Mean ± SD) | 24.1 ± 3.6 | 24.0 ± 4.3 | 0.389 |
Leave days (Mean ± SD) | 4.4 ± 10.2 | 4.5 ± 7.6 | 0.854 |
Years of employment (Mean ± SD)* | 18.4 ± 32.2 | 13.2 ± 19.8 | < 0.001 |
+Fisher’s Test; *p < 0.05 |
BMI, Body Mass Index; SD, Standard Deviation. |
The survey was distributed to 327 individuals, with a total of 306 responses (response rate: 93.6%). The cohort comprised 169 males (55.2%) and 137 females (44.8%), with an average age of 41.2 ± 10.3 years. Most participants (76.1%) utilized antigen rapid testing for COVID-19 diagnosis. Of these, 170 respondents (55.6%) were the primary economic supporters in their households.
Comparison between the Post COVID-19 Conditions group (n = 208) and the control group (n = 98) revealed no significant differences in gender distribution (p = 0.230), educational attainment (p = 0.609), primary household income source (p = 0.383), or most lifestyle habits. Notably, individuals in the Post COVID-19 Conditions group reported a shorter average employment duration compared to controls (13.2 ± 19.8 years vs. 18.4 ± 32.2 years, p < 0.001).
Symptom Analysis (Table 2)
Table 2
Symptoms Profile of COVID-19 Infected Individuals (N = 306)
| Diagnosis to end of isolation period N (%) | Three months after diagnosis N (%) | Most recent three months N (%) |
Self-perceived symptoms | 273 (89.2%) | 208 (68.0%) | 142 (46.4%) |
General symptoms | 224 (73.2%) | 83 (27.1%) | 49 (16.1%) |
Fever | 143 (46.7%) | 5 (1.6%) | 2 (0.7%) |
Fatigue | 181 (59.1%) | 83 (27.1%) | 46 (15.0%) |
Respiratory symptoms | 273 (89.2%) | 141 (46.1%) | 77 (25.2%) |
Cough | 175 (57.2%) | 102 (33.3%) | 46 (15.0%) |
Shortness of breath | 54 (17.6%) | 21 (6.9%) | 14 (4.6%) |
Chest pain/ palpitation | 24 (12.4%) | 25 (8.2%) | 12 (3.9%) |
Sore throat | 152 (49.6%) | 18 (5.9%) | 12 (3.9%) |
Runny nose/ Nasal congestion | 123 (41.2%) | 17 (5.6%) | 13 (4.2%) |
Neurological symptoms | 197 (64.4%) | 137 (44.8%) | 91 (29.7%) |
Memory impairment | 102 (33.3%) | 99 (32.4%) | 63 (20.6%) |
Headache | 80 (26.1%) | 25 (8.2%) | 18 (5.9%) |
Insomnia | 31 (10.1%) | 28 (9.2%) | 22 (7.2%) |
Dizziness | 64 (20.9%) | 32 (10.5%) | 16 (5.2%) |
Loss of smell/ taste | 71 (23.2%) | 22 (7.2%) | 10 (3.3%) |
Digestive symptoms | 50 (16.3%) | 15 (4.9%) | 10 (3.3%) |
Abdominal pain | 12 (3.9%) | 2 (0.7%) | 1 (0.3%) |
Nausea/ Vomiting/ Diarrhea | 42 (13.7%) | 10 (3.3%) | 10 (3.3%) |
Other symptoms | 141 (46.1%) | 47 (15.4%) | 36 (11.8%) |
Muscle soreness | 135 (44.1%) | 30 (9.8%) | 17 (5.6%) |
Rash | 6 (2.0%) | 4 (1.3%) | 4 (1.3%) |
Other | 3 (1.0%) | 0 (0.0%) | 1 (0.3%) |
Throughout the survey, participants reported symptoms experienced during isolation, three months post-diagnosis, and in the most recent three months: during initial isolation period, 89.2% experienced symptoms, with cough (57.2%) and sore throat (49.6%) being most common. Three months post-diagnosis, 68.0% continued to experience symptoms, notably respiratory issues (46.1%) and fatigue (27.1%). In the most recent three months, symptoms persisted in 46.4% of respondents, with neurological symptoms such as memory impairment (20.6%) becoming more prevalent.
Work Status and Health Assessments (Table 3, 4)
Table 3
Treatment and Work Status Among Post COVID-19 Conditions Group
variables | control(N = 98) | Post COVID-19 conditions (N = 208) | p-value |
Diagnosis method་ | | | |
PCR | 16 (16.3%) | 55 (26.4%) | |
Antigen rapid test | 85 (86.7%) | 157 (75.5%) | |
Treatment N(%) | | | |
Hospitalization - Intensive Care Unit | 0 (0.0%) | 0 (0.0%) | - |
Hospitalization - General Ward* | 2 (2.0%) | 20 (9.6%) | 0.017 |
Antiviral Drug Treatment | 20 (20.4%) | 47 (22.6%) | 0.666 |
Visited "COVID-19 Infected Recovery Integrated Outpatient Clinic" | 9 (9.2%) | 31 (14.9%) | 0.166 |
Night Shift/Rotating Shift* | 6 (6.1%) | 59 (28.4%) | < 0.001 |
Return-to-Work Status་ | | | |
Work from home | 17 (17.3%) | 38 (18.3%) | 0.845 |
Work adjustment * | 10 (10.2%) | 40 (19.2%) | 0.046 |
་multiple-choice question ; * p < 0.05 |
Table 4
Physical and Mental Health Assessment of Post COVID-19 Conditions Group
Assessment tool | control(N = 98) | Post covid-19 conditions(N = 208) | p-value |
Quality of Life (QoL)(Mean ± S.D)* | 84.7 ± 14.3 | 70.8 ± 16.9 | < 0.001 |
Fear of COVID-19 scale (FCS) (Mean ± SD)* | 14.6 ± 5.8 | 17.1 ± 6.9 | 0.013 |
No impact on daily life and psychology (score < 21) | 78 (79.6%) | 134 (64.4%) | |
Positive impact on daily life and Psychology (score ≥ 21) | 20 (20.4%) | 74 (35.6%) | |
Insomnia Severity Index (ISI) (Mean ± SD) | 9.18 ± 4.7 | 11.9 ± 5.5 | 0.087 |
No significant disturbance (score 0–7) | 35 (35.7%) | 50 (24.0%) | |
Slight disturbance (score 8–14) | 38 (49.0%) | 93 (44.7%) | |
Moderate disturbance (score 15–21) | 15 (15.3%) | 55 (26.4%) | |
Severe disturbance (score 22–28) | 0 (0.0%) | 10 (4.8%) | |
Work Ability Index(WAI) (Mean ± SD)* | 47.4 ± 5.7 | 44.0 ± 6.6 | 0.027 |
Excellent (score ≥ 44) | 76 (77.6%) | 118 (56.7%) | |
Good (score 37–43) | 19 (19.4%) | 59 (28.4%) | |
Moderate (score 28–36) | 2 (2.0%) | 28 (13.5%) | |
Poor (score 7–27) | 1 (1.0%) | 3 (1.4%) | |
* p < 0.05; |
SD, Standard Deviation. |
Significant findings related to employment and health post-COVID-19 were observed in the study. The Post COVID-19 Conditions group showed a higher incidence of night shifts and rotating shifts compared to controls (p < 0.001), with 19.2% requiring job adjustments post-return to work (p = 0.046). In terms of physical and mental health, Quality of Life scores indicated significantly lower physical and psychological well-being in the Post COVID-19 Conditions group compared to healthy controls (p < 0.001). Additionally, affected participants exhibited higher levels of fear of COVID-19 and insomnia severity (p = 0.013 and p < 0.001, respectively). Work ability was also impacted, with the Work Ability Index revealing reduced work capacity in the Post COVID-19 Conditions group (44.0 ± 6.6 vs. 47.4 ± 5.7, p = 0.027).
Correlation Analysis (Table 5)
Table 5
Correlation Between Post COVID-19 Conditions and Assessment Scales
| B (95% CI) | p-value | B (95% CI) + | p-value+ |
QoL* | -13.922 (-17.804, -10.039) | < 0.001 | -13.661(-17.470, -9.851) | < 0.001 |
FCS* | 2.563(0.981, 4.146) | 0.002 | 2.563 (1.001, 4.125) | 0.001 |
ISI* | 2.720(1.452, 3.988) | < 0.001 | 2.611(1.354, 3.867) | < 0.001 |
WAI* | -3.324(-4.845, -1.803) | < 0.001 | -3.313(-4.840, -1.787) | < 0.001 |
+ Adjusted for age, gender and BMI; * p < 0.05 |
BMI, Body Mass Index; CI, Confidence interval. |
Regression analysis highlighted the impact of Post COVID-19 Conditions on both health and work ability. Quality of Life scores were significantly lower in the Post COVID-19 Conditions group by an average of 13.922 points (p < 0.001). Moreover, the affected group exhibited increased scores on the Fear of COVID-19 Scale and Insomnia Severity Index, correlating with the severity of post-COVID conditions. Work Ability Index scores were reduced by 3.324 points in individuals with Post COVID-19 Conditions (p < 0.001), indicating a significant impact on work capacity.