Table 2.
Characteristics of cough
| Characteristic | All patients (N = 196) | RCC (N = 126) | UCC (N = 70) | p-value (RCC vs. UCC) | |
|---|---|---|---|---|---|
| Duration of cough, years | Mean (SD) | 6.4 (5.0) | 7.0 (5.6) | 5.3 (3.5) | 0.024 |
| Cough frequency* | Continuous, n (%) | 156 (79.6) | 94 (74.6) | 62 (88.6) | 0.024 |
| Intermittent, but not seasonal, n (%) | 34 (17.3) | 27 (21.4) | 7 (10.0) | ||
| Intermittent, seasonal, n (%) | 6 (3.1) | 5 (4.0) | 1 (1.4) | ||
| Characteristics of cough | Predominantly dry, n (%) | 171 (87.2) | 108 (85.7) | 63 (90.0) | 0.389 |
| Predominantly productive, n (%) | 25 (12.8) | 18 (14.3) | 7 (10.0) | ||
| Cough triggers** | Any trigger, n (%) | 62 (31.6) | 46 (36.5) | 16 (22.9) | 0.049 |
| Speaking or laughing, n (%) | 25 (12.8) | 16 (12.7) | 9 (12.9) | 0.975 | |
| Cold air or change in temperature, n (%) | 21 (10.7) | 14 (11.1) | 7 (10.0) | 0.810 | |
| Dust, pollen, or other air irritants/particles like perfumes, n (%) | 22 (11.2) | 19 (15.1) | 3 (4.3) | 0.031 | |
| Environmental tobacco smoke, n (%) | 13 (6.6) | 9 (7.1) | 4 (5.7) | 0.774 | |
| Agents present at work (occupational), n (%) | 2 (1.0) | 2 (1.6) | 0 (0.0) | 0.538 | |
| Eating or a particular type of food, n (%) | 17 (8.7) | 11 (8.7) | 6 (8.6) | 0.970 | |
| Exercise or exertion, n (%) | 13 (6.6) | 9 (7.1) | 4 (5.7) | 0.774 | |
| Other, n (%) | 14 (7.1) | 10 (7.9) | 4 (5.7) | 0.774 | |
| Atopy*** | Yes, n (%) | 66 (37.7) | 50 (41.0) | 16 (30.2) | 0.176 |
| Stress urinary incontinence**** | Yes, n (%) | 36 (18.4) | 21 (16.7) | 15 (21.4) | 0.409 |
RCC refractory chronic cough, SD standard deviation, UCC unexplained chronic cough
*Continuous: Patient suffers from cough every day or nearly every day. Intermittent, but not seasonal: patient suffers periods of cough and periods of remission, but the cough is not present at specific periods in the year. Intermittent, seasonal: The patient has a chronic cough at specific times or seasons
**Percentages were calculated based on cough triggers identified in patients’ clinical charts. Patients were not interrogated on these or other potential cough triggers
***Atopy, according to local standard tests (positive skin prick test or positive determination of serum-specific IgE to aeroallergens or foods)
****Stress urinary incontinence as reflected in patients’ clinical charts