PURPOSE: Two randomized controlled trials report that incorporating induced sputum cell counts into clinical management decisions reduced asthma exacerbations in well defined research environments. However, the clinical utility of sputum cells counts in ‘real world’ clinical practice has not yet been established. Induced sputum analysis was introduced into the Calgary Health Region in April 2005 as a clinical tool to aid physicians in their management decisions. The purpose of this study was to determine whether the availability of sputum cell counts to attending physicians resulted in improved asthma management, as evidenced by a reduction in the number of asthma-related emergency room visits.
METHODS: Pulmonologists, pediatricians and allergists were able to refer any patient whom they thought appropriate for sputum induction. Sputum was induced and processed using standardized methodology to determine total and differential cell counts. Reports, including a brief interpretation of how results might influence patient management, were faxed back to attending physicians within 24h. To determine the clinical utility of the test, we linked hospital records of emergency room visits to patients with physician-diagnosed asthma before and after sputum induction was performed.
RESULTS: 329 patients, aged 8-85 (mean 44) years underwent sputum induction as part of their clinical evaluation over a 21 month period. The majority of tests were done in patients with physician-diagnosed asthma, and 51% of patients had sputum eosinophilia >2% (0-80%). In the period up to 21 months prior to sputum induction, there were 57 asthma-related emergency room visits in these patients; in the equivalent period post sputum induction, there were 26 asthma-related emergency room visits (p<0.01).
CONCLUSION: The prompt availability of sputum cell counts to attending physicians likely resulted in improved clinical management of patients with asthma, as reflected by the subsequent significant reduction in asthma-related emergency room visits.
CLINICAL IMPLICATIONS: Sputum cell counts play an important role in the management of asthma patients in hospital-based clinical practice; as such, sputum cell counts should be available as the standard of care in specialist asthma clinics.
DISCLOSURE: Charity Greene, No Financial Disclosure Information; No Product/Research Disclosure Information