Risk factors for asthma attacks and poor control in children: a prospective observational study in UK primary care

Children who have had a previous attack and those with high levels of exhaled nitric oxide are at risk of a future attack. This study highlights the importance of measuring and recording these factors at asthma reviews in primary care. Objective To identify risk factors for asthma attacks and poor asthma control in children aged 5-16 years. Methods Prospective observational cohort study of 460 children with asthma or suspected asthma from 10 UK general practices. Gender, age, ethnicity, body mass index, practice deprivation decile, spirometry and fraction of exhaled nitric oxide (FeNO) were recorded at baseline. Asthma control scores, asthma medication ratio (AMR) and the number of asthma attacks were recorded at baseline and at 6 months. The above independent variables were included in binary multiple logistic regression analyses for the dependent variables of: (1) poor symptom control and (2) asthma attacks during follow-up. Results Poor symptom control at baseline predicted poor symptom control at 6 months (OR 4.4, p=0.001), while an increase in deprivation decile (less deprived) was negatively associated with poor symptom control at 6 months (OR 0.79, p=0.003). Higher FeNO levels (OR 1.02, p<0.001) and a recent history of asthma attacks (OR 2.03, p=0.02) predicted asthma attacks during follow-up. Asian ethnicity was associated with a lower OR for a future attack (OR 0.32, p=0.02). A decrease in AMR was also associated with an increased OR for future asthma attacks (OR 2.99, p=0.003) when included as an independent variable. Conclusions We identified risk factors for poor symptom control and asthma attacks in children. Routine assessment of these factors should form part of the asthma review to identify children at an increased risk of adverse asthma-related events.