Background: High levels of stress have been shown to predict the onset of asthma in children genetically at risk, and to correlate with higher asthma morbidity. Our study set out to examine whether stressful experiences actually provoke new exacerbations in children who already have asthma.
Methods: A group of child patients with verified chronic asthma were prospectively followed up for 18 months. We used continuous monitoring of asthma by the use of diaries and daily peak-flow values, accompanied by repeated interview assessments of life events and long-term psychosocial experiences. The key measures included asthma exacerbations, severely negative life events, and chronic stressors.
Findings: Severe events, both on their own and in conjunction with high chronic stress, significantly increased the risk of new asthma attacks. The effect of severe events without accompanying chronic stress involved a small delay; they had no effect within the first 2 weeks, but significantly increased the risk in the subsequent 4 weeks (odds ratio 1.71 [95% CI 1.04-2.82], p < or = 0.05 for weeks 2-4 and 2.17 [1.32-3.57], p < or = 0.01 for weeks 4-6). When severe events occurred against the backdrop of high chronic stress, the risk increased sharply and almost immediately within the first fortnight (2.98 [1.20-7.38], p < or = 0.05). The overall attack frequency was affected by several factors, some related to asthma and some to child characteristics. Female sex, higher baseline illness severity, three or more attacks within 6 months, autumn to winter season, and parental smoking were all related to increased risk of new exacerbations; social class and chronic stress were not.
Interpretation: Severely negative life events increase the risk of children's asthma attacks over the coming few weeks. This risk is magnified and brought forward in time if the child's life situation is also characterised by multiple chronic stressors.