Predicting frequent asthma exacerbations using blood eosinophil count and other patient data routinely available in clinical practice

PURPOSE: Acute, severe asthma exacerbations can be difficult to predict and thus prevent. Patients who have frequent exacerbations are of particular concern. Practical exacerbation predictors are needed for these patients in the primary-care setting. PATIENTS AND METHODS: Medical records of 130,547 asthma patients aged 12-80 years from the UK Optimum Patient Care Research Database and Clinical Practice Research Datalink, 1990-2013, were examined for 1 year before (baseline) and 1 year after (outcome) their most recent blood eosinophil count. Baseline variables predictive (P400/µL (versus ≤400/µL) increased the likelihood of two or more exacerbations >1.4-fold (odds ratio OR: 1.48 (95% confidence interval CI: 1.39, 1.58); P25-fold (OR: 25.7 95% CI: 23.9, 27.6; P<0.001). CONCLUSION: Blood eosinophil count and several other variables routinely available in patient records may be used to predict frequent asthma exacerbations.