Frequency of non-asthma GP visits predicts asthma exacerbations: an observational study in general practice.

BACKGROUND: Being able to identify patients at risk of exacerbations is useful as it enables resources to be targeted at these patients. AIMS: To test the theoretically-derived prediction that the frequency of non-asthma related visits to the general practitioner (GP) predicts exacerbations. METHODS: Clinical and demographic data and both self-report and prescription-based adherence data were obtained from 166 patients diagnosed with asthma attending a GP clinic, all of whom were prescribed inhaled corticosteroids (ICS). Asthma exacerbations (treated by the GP or in hospital) and non-asthma visits and symptoms were assessed from notes for the subsequent 5 years. RESULTS: Exacerbations correlated with non-asthma visits (0.35), severity as measured by BTS step (0.28), and with prescription-based adherence (0.28). Asthma severity correlated with non-asthma visits (0.35). Receiver operating curves showed that ≥2 non-asthma visits per year provided 79% sensitivity and 58% specificity for detecting ≥3 exacerbations over 5 years. Poor adherence predicted outcomes only for patients with high levels of non-asthma visits (≥3) and only for those reporting regular-but-less ICS use but not symptom-directed ICS use. CONCLUSIONS: Non-asthma visits are a good predictor of asthma exacerbations, particular in non-adherent patients. These results are consistent with a mechanism where exacerbations result from a combination of random oscillating specific and non-specific inflammatory processes. It is important to consider the total patient rather than just the lung when managing patients with asthma.