Effectiveness of a structured motivational intervention including smoking cessation advice and spirometry information in the primary care setting: the ESPITAP study

Smoking is the principal avoidable risk factor and etiological cause of numerous pathologies, including respiratory tract [1]. Smoking accelerates the physiological decline of pulmonary volume usually attributable to age, and the most susceptible subjects may develop chronic obstructive pulmonary disease (COPD) [2]. The estimated absolute risk of COPD for smokers is at least 25% [3]. The prevalence of COPD increases with age and is more frequent in men, but this appears to be related to the cumulative effect of other risk factors to which the individual has been exposed during a lifetime [4]. Spirometry is considered the standard test for the diagnosis and monitoring of COPD [5, 6]; nevertheless, it appears to be an inefficient screening tool for the general population. Some institutions advise against its systematic use in asymptomatic subjects for various reasons, not only cost-benefit considerations [7]. In addition, the available evidence seems to indicate that the information spirometry provides does not modify COPD management in the early stages of disease [8], when quitting a smoking habit is the most effective therapeutic intervention and the only one that increases survival [1]. Therefore, early intervention is considered crucial.

From a therapeutic perspective, smoking is a chronic disease of an addictive nature, with frequent relapses that reflect the intensity of nicotine dependence. The available data suggest that most smokers are interested in quitting and that structured advice from health professionals with whom they are in contact is an important motivating element [9]. Therefore, interventions based on individual or group counselling should be the first step in smoking cessation, with the addition of pharmacological treatment when educational strategies have not been effective [10]. In fact, the combination of advice and medication is more likely to succeed than either approach in isolation. In patients with COPD, a recent study indicates that rates of abstinence increase as interventions are added, from 2.6% with brief counselling to 12.3% when combined with drug therapy [11]. However, while it is true that adding medication significantly improves abstinence, cessation efforts often fail because of the lack of motivation of smokers [12]. In an effort to improve success rates, spirometry was advised as a motivational tool to reinforce the smoking cessation message provided by counselling [13].

Some years ago, the Lung Health Study showed that COPD could be detected early through the use of spirometry and established the benefits of smoking cessation for changing the natural history of the disease [14]. In addition, the quit rate among participants included in the intensive program was 21.7%, compared to 5.4% among subjects in the standard program [15, 16]. Bednarek et al. [17] have also published results obtained in a cohort of 4494 smokers in Poland who received a minimal intervention, placing their spirometry data on the classic Fletcher-Peto graph [18]. After 1 year of follow-up, the cessation rate was significantly higher in patients with COPD than in subjects with normal spirometry (16.3% vs 12.0%; P = 0.0003). Therefore, it is logical to assume that information about respiratory function testing could also be helpful. However, these results are from observational studies lacking sufficient statistical power to support any recommendations, leading some authors to find the evidence of the motivational merits of spirometry testing to be less than convincing [19, 20].

At present, the use of spirometry as a motivational tool for smoking cessation continues to be a controversial topic. The most recent Cochrane review of the assessment of biomedical risks as a quit-smoking aid insists that, due to the scarcity of high-quality analyses, no definitive conclusions can be reached about the effectiveness of this approach [21]. However, it also points out that spirometry had a significant effect in the only high-quality study, published in 2008 by Parkes et al. [22]. This clinical trial included 561 smokers older than 35 years who, after spirometry testing, were randomized to study groups, one of which received a summary of the results, describing their "lung age" and comparing it with their chronological age. After 12 months follow-up, abstinence rates confirmed by urinary cotinine levels were significantly higher in the intervention group (13.6% vs 6.4%, P = 0.005) and these subjects had a higher probability of abandoning their habit than those who did not receive this explanation (RR: 2.12; IC95%: 1.24-3.62). Moreover, Kotz et al. published a clinical trial in 2009 with the hypothesis that early detection of COPD and the provision of information about the results could be more effective than standard efforts to help smokers to quit [23]. The study evaluated 296 smokers aged 35-70 years with COPD detected by spirometry testing, who were randomly assigned to either confrontational counselling for smoking cessation in which a nurse respiratory specialist provided feedback on the results (experimental group) or "care as usual" for smoking cessation delivered by the general practitioner. After 52 weeks of follow-up, the intervention group achieved higher abstinence rates (11.2% vs 5.9%), although without reaching statistical significance (OR: 2.02; IC95%: 0.63-6.46). These studies appear to present contradictory results, although congruence emerges if we analyze them in detail: the use of spirometry in "healthy" smokers increases motivation (and the probability of quitting smoking), while confrontation with their lung function data is less effective in subjects with COPD. More recently, in 2010, McClure et al. [24] published a clinical trial with 536 smokers, recruited from the general North American population, who were randomized to receive a brief motivational intervention for smoking cessation (≈20 min), including spirometric testing and feedback; no differences in abstinence rates were found at 1 year of follow-up. However, in a later publication they reported that the participants with changes in their lung function tests made greater use of quit-smoking services and achieved an abstinence rate almost double that of controls at 6 months (17.2% vs 8.9%, P = 0.05; OR: 2.13, IC95%: 1.04-4.5), although the effect was diluted at 12 months (16.2 vs 11.3, P = 0.26; OR: 1.52, IC95%: 0.73-3.1) [25]. Therefore, given these other results, they concluded that more research is NEEDED to determine whether the impact of spirometry feedback differs according to the deterioration in the smoker's pulmonary function.

The main objective of this study is to evaluate the effectiveness in the primary care setting of a structured motivational intervention and feedback on spirometry data to achieve smoking cessation, compared with usual clinical practice and assessed with respect to quit rates at 12 months after the intervention.

The etiological relationship between COPD and smoking is no longer subject to discussion due to the available epidemiological, morphological and genetic evidence. There is no room for doubt that quitting smoking is the best way to reduce the risk of COPD, and is the most efficient intervention and the only effective treatment to improve survival [1]. However, smoking requires an intensive approach that is not always viable under the actual conditions of everyday clinical practice, which is often consumed with massive numbers of patient visits. Therefore, it is of fundamental importance to have evidence of ways to maximize these interventions.

The present study will evaluate, under nearly actual conditions of primary care, the efficacy of a quit-smoking strategy directed at individuals at any of the stages of change. The theoretical framework used is to provide personalized motivational information about the effects of smoking, with the goal of accelerating a change in habit. This idea is not new and was the subject of a recent Cochrane review [21]. Although certain prestigious authors and institutions [8, 20] have raised questions about the usefulness of this type of strategy, recent data allow us to assume that some patients can benefit from it [22, 25]. One plausible explanation of this apparent contradiction is that if an intervention is to succeed there must be some change in testing results and an adequate presentation of them [37]. If this were the case, being able to prove a change should have implications for clinical practice.

Primary care, with its population context and continuity of care throughout a patient's life, has a core role in any strategy to break a smoking habit. One of the main tasks of first-line care professionals is to increase patient motivation to quit smoking, and on many occasions it must be attempted in young, healthy smokers that have come to the doctor for some other reason. The ESPITAP study presents a pragmatic design that reflects these conditions, attempting to establish an intervention that can be easily applied in clinical practice. For that reason, it takes into account the usual attention these subjects receive and is intended to be incorporated into the daily clinical activity of the researchers.

The designed intervention is less intense than the one described in other studies that have taken a motivational approach, and this is not of marginal importance: a direct dose-response association has been demonstrated between intensity, success of the intervention, and abstinence rates [21]. Although one could then assume that another more intensive approach would be more appropriate, at the same time this would distance us from the conditions of daily practice that the study attempts to reflect.

A primary strength of the study is its rigorous methodology that involves a large number of health professionals and patients, which will strengthen the validity of the results. Although it will be difficult to control the extent to which the personal skills of the researchers might influence the success of the intervention, its format, content, and duration will be standardized in an effort to minimize this potential confounder.

In conclusion, the use of spirometry as a motivational instrument for smoking cessation continues to be a controversial topic. Although the available studies seem to highlight the efficacy of this intervention, there is insufficient evidence to establish definitive conclusions about its effectiveness. The results of the present study could contribute to clarify these and other questions of practical utility for primary care professionals.