| First author [ref.] | Participants | Findings |
| Tonnesen [83] | 220 asthmatics undergoing a smoking cessation programme with NRT At 4 months, 27 were abstainers, 33 reducers and 50 relapsers or continuing smokers | Improvements in the asthma-specific quality-of-life score, and reductions in self-reported day and night use of rescue β2-agonists, doses of ICS, daytime asthma symptoms and AHR were reported in the abstainers For reducers, smaller improvements occurred for night use of rescue β2-agonists, doses of ICS and AHR |
| Piccillo [72] | 57 smokers with seasonal allergic rhinitis±asthma undergoing a smoking cessation programme with NRT±bupropion At 12 months, 16 of the participants had quit smoking | A significant improvement in AHR to direct and indirect bronchoprovocation was observed after cessation in the quitters but not in the smoking cessation relapsers |
| Chaudhuri [59] | 32 asthmatic smokers given the option to quit or continue smoking 11 opted to continue smoking, whereas 10 out of 21 managed to quit smoking for up to 6 weeks | After smoking cessation, quitters achieved considerable improvement in lung function and a fall in sputum neutrophil count compared with subjects who continued to smoke |
NRT: nicotine replacement therapy; AHR: airway hyperresponsiveness; ICS: inhaled corticosteroids.