Abstract
Introduction: Chronic non-specific cough (CNSC), i.e. recurrent cough with no identifiable underlying disease, is common in childhood. It is unclear if risk factors for CNSC are similar as for wheezing illness.
We aimed to compare risk factors for CNSC with risk factors for wheeze in 0-2 year olds.
Methods: We analysed parent-completed questionnaires (response rate 79%) on 3406 children from the population-based Leicester Respiratory Cohorts. CNSC was defined as no current wheeze and a positive reply to at least 2 of the following: coughing more than others, night-time cough and cough without cold. We used multinomial logistic regression to compare potential risk factors (sex, ethnicity, family history, comorbidities, socioeconomic status (SES), exposure to infections, air pollutants, breastfeeding) between children with wheeze and those with CNSC.
Results: 353 children (10%) had CNSC and 926 (27%) wheeze. Sex (male), rhinitis, hayfever, eczema and posseting were associated with both outcomes similarly. Parental history of atopic diseases, exposure to tobacco smoke, lower SES and lack of breastfeeding were associated with wheeze only (all p<0.01). Habitual snoring was more strongly associated with wheeze than with CNSC (test for difference p=0.03). South Asian ethnicity (RRR 1.3; 95%CI 1.0-1.7; p=0.06) and nursery care (1.8; 1.4-2.3; p<0.001) were positively associated only with CNSC.
Conclusions: CNSC in 0-2 year olds has a different pattern of risk factors than wheezing illness. In particular, CNSC is less associated with personal and family history of atopy and more strongly with attendance to nursery care, suggesting infectious aetiology.
Funding: SNF PDFMP3 137033; SNF 32003B-144068; Asthma UK 07/048.
- Copyright ©ERS 2015
