Introduction The proportion of asthmatics that smoke is no different to that in the general population1,2. In patients with asthma, smoking has been associated with decline in pulmonary function, poor symptom control and reduced quality of life.
Objectives To evaluate the differences in lung function, number of asthma admissions in the previous year, asthma control, quality of life and treatment between non-smokers, ex-smokers and current smokers attending an asthma clinic. Methods: Retrospective study of 92 patients from a dedicated asthma clinic. Patients were divided into three groups - Current Smoker, Ex-Smoker and Non-Smoker. Data was obtained for spirometry results, number of hospital admissions with asthma in the preceding year, Asthma Quality of Life Questionnaire (AQLQ), Asthma Control Test (ACT) and British Thoracic Society (BTS) Step in Asthma Management.
Results See Table 1. The majority of the patients attending the asthma clinic were non-smokers 62/92 (72%), and only 9/92 (10%) were current smokers. Baseline characteristics were similar in all three groups. There were significant differences in FEV1% (p < 0.05) and FEV1/FVC ratio (p < 0.01) among the groups, despite no statistical difference in the absolute FEV1, absolute FVC and FVC%. Interestingly, the groups were similar in terms of number of hospital admissions with asthma in the preceding year, AQLQ score, ACT score and BTS step in Asthma Management.
Conclusions The proportion of smokers attending our asthma clinic is half that in the wider asthma population1. Smokers with asthma have lower FEV1 as a% of predicted and FEV1/FVC ratio than non-smokers. There were, however, no differences in other spirometric parameters, the number of hospital admissions with asthma in the preceding year, AQLQ score, ACT score and BTS step in asthma management. Smoking cessation may result in subsequent improvements in asthma control and quality of life without the need for escalating treatment.
Eisner M. Yellin E. Trupin L and Blanc P. Asthma and smoking status in a population-based study of California adults. Public Health Reports Vol. 116. pp 48–157. 2. Asthma UK Everyday asthma out of control?Asthma UK, London 2005.