Clinical definitions
| Diagnosis | Protocol definition |
|---|---|
| Protracted bacterial bronchitis | History of chronic moist cough, positive BAL culture and response to antibiotic treatment with resolution of the cough within 2 weeks |
| Natural resolution | Spontaneous resolution of cough without treatment or, if treatments were tried, there was no temporal relationship (2 weeks) with cough resolution |
| Asthma-like conditions | Episodic wheeze and cough with variable airflow limitation demonstrated by bronchodilator responsiveness16 and/or response to low dose inhaled steroids with resolution of cough within first 2 weeks of treatment |
| Bronchiectasis | History of chronic cough and the presence of radiological bronchiectasis on HRCT scan of the chest17 |
| Aspiration lung disease | Children with recurrent cough with feeds and patchy changes on chest radiograph.9 The diagnosis was made on resolution of cough on withdrawing oral fluids combined with supportive investigations including modified barium swallow and HRCT changes |
| Gastro-oesophageal reflux | Reflux index (% time pH <4) of ⩾4% on pHmetry or oesophageal biopsy showing reflux oesophagitis18 and treatment by standard medical therapy results in resolution of the cough |
| Eosinophilic lung disorders | Included eosinophilic bronchitis or hypereosinophilic syndrome. Eosinophilic bronchitis was defined as an eosinophil count of >1% of BAL cellular differential or >2.5% of induced sputum cellular differential16 |
| Upper airway cough syndrome | Cough due to upper airway conditions with a history consistent with diagnosis and response to specific intranasal treatment within 2 weeks19 |
| Bordetella pertussis and Mycoplasma pneumoniae infections | Diagnosis made if serological evidence of infection (B pertussis IgA positive, rising total antibody titres to M pneumoniae) and evidence of these organisms in BAL using PCR |