Table 1.
Demographics and clinical characteristics between the PBB and the non-PBB group.
| PBB (N = 55) | non-PBB (N = 220) | P-value | |
|---|---|---|---|
| Female sex | 34 (61.8) | 112 (50.9) | 0.147 |
| Age (ys) | 46.0 (32.0–52.0) | 39.5 (30.0–53.0) | 0.350 |
| Smoking status | |||
| Never smoker | 48 (87.3) | 192 (87.3) | 0.999 |
| Ex-smoker | 6 (10.9) | 17 (7.7) | 0.422 |
| Current smoker | 1 (1.8) | 11 (5.0) | 0.470 |
| Cough duration (mon) | 3.0 (1.4–8.5) | 24.0 (9.0–90.0) | <0.001 |
| Productive cough | 45 (81.8) | 69 (32.2) | <0.001 |
| Yellow phlegm | 28 (50.9) | 12 (5.6) | <0.001 |
| URTI as an initial factor | 37 (67.3) | 94 (42.7) | 0.001 |
| Seasonality | 7 (12.7) | 165 (22.2) | 0.120 |
| Occupational or environmental exposure | 14 (25.5) | 36 (16.4) | 0.118 |
| Timing of cough | |||
| Daily cough | 48 (87.3) | 194 (88.2) | 0.853 |
| Nocturnal cough | 22 (40.0) | 80 (36.4) | 0.618 |
| Triggers | |||
| Dust | 27 (49.1) | 96 (43.6) | 0.467 |
| Cold air | 24 (43.6) | 93 (42.3) | 0.855 |
| Cooking smell | 25 (45.5) | 102 (46.4) | 0.904 |
| Cigarette smoke | 20 (36.4) | 89 (40.5) | 0.579 |
| Lying down | 10 (18.2) | 36 (16.4) | 0.747 |
| Talking | 18 (32.7) | 85 (38.6) | 0.418 |
| Concomitant symptoms | |||
| Itchy throat | 33 (60.0) | 130 (59.1) | 0.902 |
| Itching below the throat | 14 (25.5) | 53 (24.1) | 0.833 |
| Pharyngeal foreign body sensation | 20 (36.4) | 82 (37.3) | 0.901 |
| Throat clearing | 16 (29.1) | 90 (40.9) | 0.107 |
| SMIT | 37 (67.3) | 87 (39.5) | <0.001 |
| Postnasal dripping | 16 (29.1) | 49 (22.3) | 0.287 |
| Runny nose | 15 (27.3) | 60 (27.3) | 0.999 |
| Acid regurgitation | 5 (9.1) | 38 (17.3) | 0.135 |
| Heartburn | 5 (9.1) | 20 (9.1) | 0.999 |
| Cough severity evaluation | |||
| Cough VAS (mm) | 3.0 (2.0–4.0) | 3.0 (2.0–4.0) | 0.236 |
| Daytime cough scores | 1.0 (1.0–2.0) | 1.0 (1.0–2.0) | 0.283 |
| Night-time cough scores | 50.0 (30.0–70.0) | 60.0 (50.0–70.0) | 0.292 |
| Medical history | |||
| Rhinitis | 9 (16.4) | 52 (23.6) | 0.246 |
| Sinusitis | 6 (10.9) | 31 (14.1) | 0.536 |
Continuous variables were expressed as median (inter-quartile range, IQR). Categorical variables were presented as n (%). Among 220 patients with non-PBB, cough characteristics and sputum color were recorded in 214 patients, and cough seasonality in 212 patients. PBB: protracted bacterial bronchitis; URTI: upper respiratory tract infection; SMIT: a sensation of mucus in the throat; VAS: visual analogue scale.