Table 1
Descriptive statistics for 70 asthmatic children.
| VARIABLES | ALL PATIENTS (%) | |
|---|---|---|
| Age (years) | 9.7 (5.3, 18) | |
| Gender | Male | 47 (67.1) |
| Female | 23 (32.9) | |
| OPD | Chest Clinic (Bangkok) | 39 (55.7) |
| Allergy Clinic (Bangkok) | 18 (25.7) | |
| Chest Clinic (Chiang Mai) | 13 (18.6) | |
| Comorbidity | Allergic Rhinitis | 38 (54.3) |
| Atopic Dermatitis | 2 (2.9) | |
| Level of asthma controlled | Well Controlled | 41 (58.6) |
| Partly/Uncontrolled | 29 (41.4) | |
| Severity of asthma | Mild | 16 (22.9) |
| Moderate | 16 (22.9) | |
| Severe | 38 (54.3) | |
| Environmental factors | Passive Smoking | 14 (20) |
| Pets | 23 (32.9) | |
| Air Purifier | 26 (37.1) | |
Figure 1
Study area in overview (A), the location of air monitoring station and residence of participants in each study site (Ramathibodi Hospital and Nakornping Hospital) are illustrated in B. and C. respectively.
Figure 2
The average individual PM2.5 exposure.
Figure 3
Incidence of asthma exacerbation among participants during the study period (June 2020 to February 2021).
Table 2
Factors affecting asthma exacerbation.
| FACTORS | EXACERBATION N = 32 (%) | NO EXACERBATION N = 38 (%) | P-VALUE | |
|---|---|---|---|---|
| Asthma status before enrollment | Control (n = 41) | 6 (14.6) | 35 (85.4) | <0.001 |
| Uncontrol (n = 29) | 26 (89.7) | 3 (10.3) | ||
| Severity of asthma | Mild (n = 16) | 6 (37.5) | 10 (62.5) | 0.69 |
| Moderate (n = 16) | 7 (43.8) | 9 (56.2) | ||
| Severe (n = 38) | 19 (50) | 19 (50) | ||
| Air purifier used | 12 (46.1) | 14 (53.9) | 0.95 | |
| Passive smoking | 7 (50) | 7 (50) | 0.72 | |
| Pet | 10 (43.3) | 13 (56.6) | 0.79 | |
Table 3
Hazard ratios for asthma exacerbation.
| FACTORS | HAZARD RATIO | 95% CI | P-VALUE |
|---|---|---|---|
| PM2.5 level | 0.99 | 0.95, 1.03 | 0.8 |
| Age | 0.79 | 0.68, 0.93 | 0.004 |
| Female | 1.45 | 0.7, 2.96 | 0.3 |
| Air purifier used | 0.88 | 0.42, 1.85 | 0.75 |
Figure 4
PM2.5 concentration and Lag Day 3 between exacerbation group and non-exacerbation group.
Figure 5
The association of PM2.5 increment and asthma exacerbation.