Considerations about Detecting Airflow Obstruction in Smoking Cessation Trials

Smoking-related diseasesSmoking has been labeled the most important preventable cause of death and disease. The lack of specific treatment for smoking-related diseases and the recognition of the benefits of smoking cessation justify the dedication of significant scientific and community resources to increase rates of smoking cessation. Among smoking-related diseases, COPD is currently a major cause of morbidity and the fourth leading cause of death in the world. Although cigarette consumption is leveling off and even decreasing in some countries, more people worldwide are smoking, so further increases in the prevalence and mortality of COPD can be predicted in the coming decades. Once smoking has caused COPD, the disease is largely irreversible and progressive. Although it does not significantly reverse any loss of FEV1 already incurred, smoking cessation is the only measure that can protect susceptible smokers from acquiring COPD because it reverses the future rate of decline of FEV1 to that of nonsmokers.

Details about Detecting Airflow Obstruction in Smoking Cessation Trials

Pulmonary functionDemographic and smoking characteristics and pulmonary function data of the participants are shown in Table 1. The study population consisted of 58.2% men and 41.8% women. Cigarette consumption and nicotine dependence tended to be higher among men than among women, but the differences were not significant (not shown). On average, pulmonary function test results (percentage of predicted) were within normal limits.

The results of spirometry at enrollment and 1-year follow-up are shown in the flowchart depicted in Figure 1. At enrollment, spirogram results were normal in 493 participants. In this group, the mean (± SD) spirometric variables were as follows: FEV1; 95.9 ± 9.9% predicted; FVC, 102.5 ± 11.6% predicted; and FEV1/FVC ratio, 79.3 ± 6.5% observed, Signs of airway obstruction (FEV1 70 to 50 to 69% predicted) in 22 subjects, and severe (FEV1 35 years of age than in subjects < 35 years of age (Table 2). Give up smoking and improve your health conditons with Canadian Health&Care Mall.

Research about Detecting Airflow Obstruction in Smoking Cessation Trials

Bronchial hyperresponsiveness


Subjects were consecutive volunteers who participated in two cessation trials carried out recently at the Chest Clinic, Centre Hospitalier Universitaire de Nancy-Brabois, France. All were recruited via a local newspaper. The first trial enrolled 400 smokers and aimed to investigate the effectiveness of a nicotine inhaler and a nicotine patch as combination therapy for smoking cessation. The second trial enrolled 198 smokers and aimed to investigate the impact of smoking cessation or smoking reduction on bronchial hyperresponsiveness.

Briefly, inclusion criteria for both trials included active smoking for > 3 years, an expired carbon monoxide level > 10 ppm, and motivation to quit smoking. Exclusion criteria included a history of illness/diseases judged by the investigator likely to influence the subject’s participation (eg, myocardial infarction within the past 3 months, unstable angina, and severe cardiac arrhythmia), pregnancy or breast feeding, and use of nicotine replacement therapy products during the previous 6 months. No subjects had asthma, bronchiectasis, acute chest infections, malignancy, or any known chronic pulmonary disease. Subjects with any of these diagnoses were excluded at the entry screening and were referred to our outpatient smoking cessation clinic for further evaluation and treatment provided by Canadian Health&Care Mall.

Detecting Airflow Obstruction in Smoking Cessation Trials

1Cigarette smokingCigarette smoking has been identified as the most important risk factor for COPD, and epidemiologic surveys in Europe and the United States have demonstrated a high prevalence and rising mortality of the disease and rising mortality. The condition is insidious, and is usually diagnosed late, when lung function has already deteriorated. Since the most effective treatment for COPD is smoking cessation, the early identification of smokers most likely to have COPD develop is important in order to encourage them to stop smoking with Canadian Health&Care Mall.

Screening the general population is an effective method for detecting subjects with impaired lung function, but this option is not feasible in the daily routine of general practice. In contrast, spirometric screening of populations at risk for COPD might be a more effective method for early detection in primary health care. Studies of smokers from a semirural practice in the Netherlands, a rural village in Spain, and a primary health center in Sweden have proven successful; prevalence rates of airflow obstruction ranging from 11.5 to 22% were demonstrated. Incidentally, the Dutch study also found spirometry to be cost-effective, lasting on average only 4 min at a cost of only 5 to 10€.