Supporting smoking cessation in chronic obstructive pulmonary disease with behavioral intervention: a randomized controlled trial

Peian Lou 0 Yanan Zhu 1 Peipei Chen 0 Pan Zhang 0 Jiaxi Yu 0 Ning Zhang 0 Na Chen 0 Lei Zhang 0 Hongmin Wu 1 Jing Zhao 1 0 The Xuzhou Center for Disease Control and Prevention , 142 West Erhuan Road, Xuzhou City, Jiangsu Province, People's Republic of China 221006 1 Department of Respiratory Medicine, Hospital of Xuzhou medical college , 99 West Huaiai Road, Xuzhou City, Jiangsu Province, People's Republic of China 221006 Background: Cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD). But a fewer smoking cessation measures were conducted in communities for smokers with COPD in China. The aim of our study was to assess the preventive effects of behavioral interventions for smoking cessation and potential impact factors in smokers with COPD in China. Methods: In a randomised controlled smoking cessation trial 3562 patients with COPD who were current smoker were allocated to intervention group received behavioral intervention and control group received the usual care for two years. The primary efficacy endpoint was the complete and continuous abstinence from smoking from the beginning of month 24 to the end of month 30. Participants were followed up at month 48. Results: Continuous smoking abstinence rates from month 24 to 30 were significantly higher in participants receiving behavioral intervention than in those receiving usual care (46.4% vs 3.4%, p < 0.001). Continuous abstinence rates from months 24 to 36 (45.8% vs 4.0%) and months 24 to 48 (44.3% vs 5.1%) were also higher in participants receiving behavioral intervention than in those control group. Family members or family physicians/ nurses smoking were first identified to influence smoking cessation. Conclusions: Behavioral intervention doubled the smoking cessation rate in patients with COPD and was complied well by the general practitioners. The family members and family physicians/nurses smoking were the main risk factors for smoking cessation. Trial registration: Chinese Clinical Trials Registration (ChiCTR-TRC-12001958). - Background Chronic obstructive pulmonary disease (COPD) is a progressive systemic inflammatory disease that is usually an abnormal response to noxious particles and gases (more often, tobacco smoke) in susceptible individuals. Cigarette smoking is a worldwide risk factor for COPD [1,2], which accounts for 80-90% of COPD patients [3]. Lkke and colleagues found that smoking significantly increased the cumulative incidence of COPD in a 25 year follow up study [4]. The highest incidence for all stages of COPD was 35.5% that occurred in continuous smokers, while the incidence of never smokers was only 7.8% [4]. Comparing cigarette smoking status in COPD patients, Zhou et al. found that the greater amount of smoking, the deeper inhalation into the airway and start smoking at earlier age had the greater risks of COPD [5]. Kanner et al. investigated mild stage of COPD patients continuously smoking, the speed of forced expiratory volume in 1 second (FEV1) was declined when suffered from the lower airflow illness. Stopping smoking protected these people with mild COPD from this additional loss of lung function [6]. Quitting smoking is the most cost-effective method to prevent lung function deterioration for COPD patients. A longitudinal cohort study showed that continuous smokers had a much steep decline of lung function than those stopped smoking, while never smokers had the best lung function [7]. Lung Health Study confirmed that smoking cessation could reduce smoking-related decline in lung function [8,9]. When COPD patients with severely impaired lung function stopped smoking, their lung function might be not recovered, but the subsequent decline tend to be normal [10,11]. On the other hand, smoking cessation also improved airway hyperresponsiveness for COPD patients [12]. Smoking cessation at the early stage was able to benefit COPD prognosis [7,8,11,13], which was more effective than stop smoking at the later stages [14]. These data suggested the importance of COPD patients quit smoke as early as possible [5]. In China, over 40 million people suffered from COPD, and more than 1.28 million died from it every year [15]. About 80-90% of patients with COPD were smokers [16]. Although efficacious smoking cessation methods have been established for patients with COPD [17-19], no more stringent advice or pharmacological therapies have been applied for COPD patients to quit smoking compared with general smokers [20], and examined the influencing factors of community-based smoking cessation trial in current smokers with COPD in China especially. In present study, we conducted a randomized controlled trial to assess the efficacy of a two-year course of behavioral interventions on helping patients with COPD to quit 14 healthcare centers Behavioral intervention 7 healthcare centers 1,814 were allocated in 7 healthcare centers Received allocated intervention (n=1,793) Refused to participate: n=21. 1,748 were allocated in seven communities Received allocated intervention (n=1,730) Refused to participate: n=18. Lost to follow-up (unable to contact: n=20) Discontinued intervention (died: n=370) Lost to follow-up (unable to contact: n=26) Discontinued intervention (died: n=457) Figure 1 Consort figure of the trial profile. smoking, and explore potential factors potentially barring smoking cessation. Methods Study design The study was a randomized controlled trial conducted form from January 2008 to May 2012, which involves three months patients recruitment, two years intervention, two years monitoring. Recruitment of practices took place in 28 communities based on our previous epidemiological study [21]. Fourteen healthcare centers enrolled in the study; General healthcare centers in the intervention group received support to implement the behavioral intervention program, whereas the control healthcare centers delivered usual care. Randomization took place on healthcare center level. The healthcare centers were classified in two classes: with high or low task delegation from general practitioners to nurses. The healthcare centers in the classes were then randomly allocated to the groups (See: consort Figure 1). A two-sided P value < 0.05 was used. Based on a twosided Type 1 error () = 0.05, with an 80% power to detect a 25% relative reduction in quitting rates, allowing 20% loss during follow-up, we need that each group should contain a minimum of 7 healthcare centers s and at least 50 patients with COPD per group. This study was approved by the Ethics Committee of the Xuzhou Center for Disease Control and Prevention and the Regional Ethical Vetting Board, Xuzhou, China. In addition, agreement was received from all of the relevant health centers. Informed consent was obtained from all participants. Subjects Patients were recruited by their family physicians from 14 healthcare units in rural area of Xuzhou city, China, from January to March 2008. Patients h (...truncated)