| First author [ref.] | Agent | Persistence of exposure | Cessation of exposure | ||
| Symptom recovery | NSBHR recovery | Symptom recovery | NSBHR recovery | ||
| Chan-Yeung [13] | Red cedar | 0/47 | NA | 55/136 | NA |
| Rosenberg [14] | Isocyanates | 0/4 | 0/4 | 10/20 | 0/14 |
| Moscato [15] | Various | 0/4 | NA | 9/18 | NA |
| Gannon [16] | Various | 2/34 | NA | 3/78 | NA |
| Tarlo [17] | Isocyanates | 0/10# | NA | 23/104# | NA |
| Orriols [18] | Isocyanates | 0/4 | 0/4 | 10/17 | 6/17 |
| Merget [19] | Platinum salts | 0/9 | NA | 10/19 | NA |
| Valentino [20] | Isocyanates | 0/13 | NA | 9/37 | NA |
| Padoan [21] | Isocyanates | 2/13 | NA | 23/74 | NA |
| Pooled estimates¶ | 4/138, 7.0% (3.4–13.7%) | 0/8 | 152/503, 33.7% (23.6–45.6%) | 6/31 | |
Individual study data are presented as n/N. Pooled estimates are presented as n/N with or without % (95% CI). NA: not available; NSBHR: nonspecific bronchial hyperresponsiveness. #: “Global assessment of asthma”; ¶: pooled estimates based on a random-effect model.