Background Elevated sputum eosinophil counts predict asthma exacerbations and responsiveness to inhaled corticosteroids but are impractical to measure in primary care. We investigated the relation between blood eosinophil count and prospective annual asthma outcomes for a large UK cohort. Methods This historical cohort study used anonymised medical record data to identify primary care patients with asthma aged 12–80 years with 2 years of continuous records, including 1 year before (baseline) and 1 year after (outcome) their most recent eosinophil count. Negative binomial regression was used to compare outcome exacerbation rates and logistic regression to compare odds of asthma control for patients with blood eosinophil counts of 400 cells per μL or less versus greater than 400 cells per μL, adjusting for age, sex, body-mass index, smoking status, and Charlson comorbidity index. The study is registered at ClinicalTrials.gov, number NCT02140541. Findings Overall, 20 929 (16%) of 130 248 patients had blood eosinophil counts greater than 400 cells per μL. During the outcome year, these patients experienced signifi cantly more severe exacerbations (adjusted rate ratio [RR] 1·42, 95% CI 1·36–1·47) and acute respiratory events (RR 1·28, 1·24–1·33) than those with counts of 400 cells per μL or less. They also had signifi cantly lower odds of achieving overall asthma control (OR 0·74, 95% CI 0·72–0·77), defi ned as limited reliever use and no asthma-related hospital attendance or admission, acute course of oral corticosteroids, or prescription for antibiotics. Exacerbation rates increased progressively with nine ascending categories of blood eosinophil count as compared with a reference category of 200 cells per μL or less. Interpretation Patients with asthma and blood eosinophil counts greater than 400 cells per μL experience more severe exacerbations and have poorer asthma control. Furthermore, a count–response relation exists between blood eosinophil counts and asthma-related outcomes. Blood eosinophil counts could add predictive value to Global Initiative for Asthma control-based risk assessment

PurposeAcute, 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 methodsMedical 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 (P<0.05) of exacerbation in the outcome year were compared between patients who had two or more exacerbations and those who had no exacerbation or only one exacerbation, using uni- and multivariable logistic regression models. Exacerbation was defined as asthma-related hospital attendance/admission (emergency or inpatient) or acute oral corticosteroid (OCS) course.ResultsBlood eosinophil count >400/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); P<0.001). Variables that significantly increased the odds by up to 1.4-fold included increasing age (per year), female gender (versus male), being overweight or obese (versus normal body mass index), being a smoker (versus nonsmoker), having anxiety/depression, diabetes, eczema, gastroesophageal reflux disease, or rhinitis, and prescription for acetaminophen or nonsteroidal anti-inflammatory drugs. Compared with treatment at British Thoracic Society step 2 (daily controller ± reliever), treatment at step 0 (none) or 1 (as-needed reliever) increased the odds by 1.2- and 1.6-fold, respectively, and treatment at step 3, 4, or 5 increased the odds by 1.3-, 1.9-, or 3.1-fold, respectively (all P<0.05). Acute OCS use was the single best predictor of two or more exacerbations. Even one course increased the odds by more than threefold (OR: 3.75 [95% CI: 3.50, 4.01]; P<0.001), and three or more courses increased the odds by >25-fold (OR: 25.7 [95% CI: 23.9, 27.6]; P<0.001).ConclusionBlood eosinophil count and several other variables routinely available in patient records may be used to predict frequent asthma exacerbations.

Prescribing patterns in chronic obstructive pulmonary disease (COPD) are often inconsistent with published guidelines. This retrospective, observational study utilised data from the Optimum Patient Care Research Database to examine the changes in COPD prescribing patterns over time and to identify predictors of physician treatment choice for patients newly diagnosed with COPD. Initial therapy was defined as the treatment(s) prescribed at or within 1 year before COPD diagnosis. Changes over time were assessed in three cohorts based on the date of diagnosis: (1) 1997–2001; (2) 2002–2006; and (3) 2007–2010. Factors affecting the odds of being prescribed any initial therapy or any initial maintenance therapy were identified by univariable and multivariable logistic regression. The analysis included 20,154 patients, 45% of whom were prescribed an initial regimen containing an inhaled corticosteroid (ICS), whereas 28% received no initial pharmacological treatment. Prescribing of ICS monotherapy decreased over time, as did the proportion of patients receiving no therapy at or within 1 year before diagnosis. Comorbid asthma, a high exacerbation rate, increased symptoms and poor lung function each increased the likelihood of being prescribed any initial therapy or initial maintenance therapy; comorbid asthma and an annual rate of ⩾3 exacerbations were the strongest predictors. In conclusion, our analyses revealed major differences between actual prescribing behaviour and guideline recommendations for patients with newly diagnosed COPD, with many patients receiving no treatment and large numbers of patients receiving ICS-containing regimens. Predictors of initial therapy were identified.

BackgroundUsing a metered-dose inhaler (MDI) beyond the labeled number of actuations may result in inadequate dosing of medication, which can lead to poor clinical outcomes. This study compared respiratory-related emergency department (ED) visit rates in patients with asthma, chronic obstructive pulmonary disease, or both when they used albuterol MDIs with versus without dose counters.MethodsThis retrospective study used US claims data to identify patients (ages 4–64 years) with asthma, chronic obstructive pulmonary disease, or both, using albuterol MDIs with or without an integrated dose counter. The study comprised a 1-year baseline period for patient characterization and confounder definition and a 1-year outcome period following the first albuterol prescription. The primary end point was the incidence rate of respiratory-related ED visits, compared using a reduced zero-inflated Poisson regression model. We also compared severe exacerbation rates and rescue medication use.ResultsA total of 93,980 patients were studied, including 67,251 (72%) in the dose counter cohort and 26,729 (28%) in the non-dose-counter cohort. The cohorts were broadly similar at baseline (55,069 [59%] female patients; median age, 37 years). The incidence rate of respiratory-related ED visits during the outcome year was 45% lower in the dose counter cohort than in the non-dose-counter cohort (adjusted rate ratio: 0.55; 95% confidence interval: 0.47–0.64). Exacerbation rates and short-acting β-agonist use were similar between cohorts.ConclusionThese findings suggest that dose counter integration into albuterol MDIs is associated with decreased ED visit rates. The presence of integrated dose counters on rescue inhalers can help patients avoid using an empty or near-empty inhaler during exacerbations, thereby ensuring available medication for relief of their symptoms. Integrated dose counters on rescue MDIs could represent a simple and effective tool to improve clinical outcomes during exacerbations, with a potential for cost savings to health care systems.

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