S62 A Systematic Review of Factors Associated with Future Asthma Attacks to Inform a Risk Assessment Questionnaire

Abstract

Rationale Some clinical outcomes are worse in current smokers and ex-smokers with mild to moderate asthma compared to never smokers, but little is known about the influence of smoking status in severe asthma. Objectives The objectives of the analysis were to examine the association of current or previous cigarette smoking with clinical and inflammatory variables in severe asthma. Methods We compared patient demographics, disease characteristics and biomarkers of inflammation in never smokers (n=461, 62.3%), ex-smokers (n=210, 28.4%) and current smokers (n=69, 9.3%) with refractory asthma (n=760) recruited to the British Thoracic Society Severe Asthma Registry. Results Current smokers had poorer asthma control, more unscheduled health care visits, more rescue courses of oral steroids and higher anxiety and depression scale scores than ex-smokers or never smokers. Compared to never smokers, current smokers had a reduced proportion of sputum eosinophils (3.75% and 1.25% respectively) and lower fraction of exhaled nitric oxide (Fe NO50 ) values (35 ppb versus 14 ppb), whereas ex-smokers had an increased proportion of sputum neutrophils (43.8% versus 56.9%), but similar proportion of sputum eosinophils (2.8%) and Fe NO50 values (35 ppb). Both current and ex-smokers had reduced serum specific IgE levels to some common environmental allergens. Conclusion Current smokers with severe asthma exhibit worse outcomes for a range of clinical and health care variables compared to exsmokers and never smokers with severe asthma. Inflammatory profiles in sputum and blood differ between current smokers, ex-smokers and never smokers, possibly constituting separate phenotypes of severe asthma, which may influence responses to targeted therapies. Asthma attacks occur across all subtypes and severities of disease. Accurate quantification of asthma attack risk would enable targeting of interventions with a potential reduction in morbidity, mortality, and costs. We aimed to develop a risk assessment questionnaire underpinned by a systematic literature review. We searched major databases up to February 2012 using the terms: asthm* AND (exacerbati* OR admission) AND (risk OR predic* OR associat*) NOT review. A SYSTEMATIC REVIEW OF FACTORS ASSOCIATED WITH FUTURE ASTHMA ATTACKS TO INFORMIncluded studies were those in individuals >12 years old with doctor-diagnosed asthma on treatment. Outcomes were asthma attacks defined as: deterioration of symptoms, fall in objective measures of airflow, and need for a short course of augmented asthma therapy OR admission to hospital OR attendance at emergency department. Statistical analysis was carried out using RevMan 5 and SPSS 19.3536 unique publications were retrieved. After title screening and comparison of abstracts against a standard checklist and age criteria, data extraction was undertaken in duplicate on the remaining 143 papers (see figure).Of 18 major research themes identified, 8 factors had a consistent and clinically important (OR>1.25) association with asthma attacks across publications ...

Identifying Risk of Future Asthma Attacks Using UK Medical Record Data: A Respiratory Effectiveness Group Initiative

“…12 Available guidelines do discuss future risk, 13,14 and there are a large number of publications that report single or grouped risk factors for asthma attacks. [13][14][15] A simple risk questionnaire based on such published risk factors 16 has generated substantial public interest.…”

Prediction of individual outcomes for asthma sufferers

“…Prior efforts to predict future exacerbation events focused on specific risk factors available in cross-section (e.g. lung function, blood eosinophil levels, prior exacerbations, or a combination of these and other factors) (Bateman, Buhl, O'Byrne, Humbert, Reddel, Sears, Jenkins, Harrison, Quirce, Peterson et al, 2015;Blakey, Woulnough, James, Fellows, Obeidat, Navaratnam, Stringfellow, Yeoh, Pavord, Thomas et al, 2012). However, each individual with asthma may have a differential response to medications over time.…”