Drivers of year-to-year variation in exacerbation frequency of COPD: analysis of the AERIS cohort.

The association between exacerbation aetiology and exacerbation frequency is poorly understood. We analysed 2-year follow-up data from a prospective observational study of patients with chronic obstructive pulmonary disease (COPD) (www.clinicaltrials.gov identifier number NCT01360398) to evaluate year-to-year variation in exacerbation frequency and related aetiology. A total of 127 patients underwent blood and sputum sampling monthly and at exacerbation to detect respiratory infections and eosinophilic inflammation; 103 continued into year 2 and 88 completed both years. The most common bacterial species at stable state and exacerbation was Haemophilus influenzae. Among infrequent exacerbators (one exacerbation per year), the incidence of viral infection at exacerbation was high (60.0% (95% CI 35.1-81.7%) in year 1 and 78.6% (53.4-94.2%) in year 2). Those with more frequent exacerbations tended to have higher relative incidence of bacterial than viral infection. Patients with at least two additional exacerbations in year 2 versus year 1 had a higher risk of H. influenzae colonisation at stable state than those with at least two fewer exacerbations, as detected by culture (OR 1.43 (95% CI 0.71-2.91) versus 0.63 (0.40-1.01), p=0.06) and PCR (1.76 (95% CI 0.88-3.51) versus 0.56 (0.37-0.86), p<0.01). This was not seen with other infection types or eosinophilic inflammation. Analysis of the same cohort over 2 years showed, for the first time, that changes in yearly COPD exacerbation rate may be associated with variations in H. influenzae colonisation.

Impact and associations of eosinophilic inflammation in COPD: analysis of the AERIS cohort.

Eosinophilic inflammation in chronic obstructive pulmonary disease (COPD) predicts response to treatment, especially corticosteroids. We studied the nature of eosinophilic inflammation in COPD prospectively to examine the stability of this phenotype and its dynamics across exacerbations, and its associations with clinical phenotype, exacerbations and infection.127 patients aged 40-85 years with moderate to very severe COPD underwent repeated blood and sputum sampling at stable visits and within 72 h of exacerbation for 1 year.Blood eosinophils ≥2% was prevalent at baseline, and predicted both predominantly raised stable-state eosinophils across the year (area under the curve 0.841, 95% CI 0.755-0.928) and increased risk of eosinophilic inflammation at exacerbation (OR 9.16; p<0.001). Eosinophils ≥2% at exacerbation and eosinophil predominance at stable visits were associated with a lower risk of bacterial presence at exacerbation (OR 0.49; p=0.049 and OR 0.25; p=0.065, respectively). Bacterial infection at exacerbation was highly seasonal (winter versus summer OR 4.74; p=0.011) in predominantly eosinophilic patients.Eosinophilic inflammation is a common and stable phenotype in COPD. Blood eosinophil counts in the stable state can predict the nature of inflammation at future exacerbations, which when combined with an understanding of seasonal variation provides the basis for the development of new treatment paradigms for this important condition.

Reducing hospital admissions and improving the diagnosis of COPD in Southampton City: methods and results of a 12-month service improvement project.

BACKGROUND: The British Lung Foundation highlighted Southampton City as a hotspot for patients at future risk of chronic obstructive pulmonary disease (COPD) exacerbations due to severe deprivation levels and a high undiagnosed level of disease based on health economic modelling. We developed a strategy spanning primary and secondary care to reduce emergency admissions of patients with acute exacerbations of COPD and increase the diagnosed prevalence of COPD on general practitioner (GP) registers closer to that predicted from local modelling. METHODS: A comprehensive 3-year audit of admissions was performed. Patients who had been admitted with an exacerbation to University Hospital Southampton three or more times in the previous 12 months were cohorted and cared for in a consultant-led, but community based, COPD service. Within primary care, a programme of education and case-based finding was delivered to most practices within the city. RESULTS: Thirty-four patients were found to be responsible for 176 admissions (22% of total COPD admissions) to the hospital. These 34 patients required 185 active interventions during the 12-month period but only 39 hospital admissions. The 30-day readmission rate dropped from 13.4 to 1.9% (P<0.01), confirming the contribution the cohort made to readmissions. Prior to the project, the registered Quality Outcomes Framework prevalence of COPD within the city was 1.5; after just 1 year of the project, the prevalence increased from 1.5 to 2.27%. CONCLUSIONS: The use of medical intelligence to investigate the underlying processes of COPD hospital admissions led to an effective intervention delivered in a consultant-led model.