Biomedical risk assessment as an aid for smoking cessation.

BACKGROUND: A possible strategy for increasing smoking cessation rates could be to provide smokers who have contact with healthcare systems with feedback on the biomedical or potential future effects of smoking, e.g. measurement of exhaled carbon monoxide (CO), lung function, or genetic susceptibility to lung cancer. We reviewed systematically data on smoking cessation rates from controlled trials that used biomedical risk assessment and feedback. OBJECTIVES: To determine the efficacy of biomedical risk assessment provided in addition to various levels of counselling, as a contributing aid to smoking cessation. SEARCH STRATEGY: We systematically searched he Cochrane Collaboration Tobacco Addiction Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to 2004), and EMBASE (1980 to 2004). We combined methodological terms with terms related to smoking cessation counselling and biomedical measurements. SELECTION CRITERIA: Inclusion criteria were: a randomized controlled trial design; subjects participating in smoking cessation interventions; interventions based on a biomedical test to increase motivation to quit; control groups receiving all other components of intervention; an outcome of smoking cessation rate at least six months after the start of the intervention. DATA COLLECTION AND ANALYSIS: Two assessors independently conducted data extraction on each paper, with disagreements resolved by consensus. MAIN RESULTS: From 4049 retrieved references, we selected 170 for full text assessment. We retained eight trials for data extraction and analysis. One of the eight used CO alone and CO + Genetic Susceptibility as two different intervention groups, giving rise to three possible comparisons. Three of the trials isolated the effect of exhaled CO on smoking cessation rates resulting in the following odds ratios (ORs) and 95% confidence intervals (95% CI): 0.73 (0.38 to 1.39), 0.93 (0.62 to 1.41), and 1.18 (0.84 to 1.64). Combining CO measurement with genetic susceptibility gave an OR of 0.58 (0.29 to 1.19). Exhaled CO measurement and spirometry were used together in three trials, resulting in the following ORs (95% CI): 0.6 (0.25 to 1.46), 2.45 (0.73 to 8.25), and 3.50 (0.88 to 13.92). Spirometry results alone were used in one other trial with an OR of 1.21 (0.60 to 2.42).Two trials used other motivational feedback measures, with an OR of 0.80 (0.39 to 1.65) for genetic susceptibility to lung cancer alone, and 3.15 (1.06 to 9.31) for ultrasonography of carotid and femoral arteries performed in light smokers (average 10 to 12 cigarettes a day). AUTHORS' CONCLUSIONS: Due to the scarcity of evidence of sufficient quality, we can make no definitive statements about the effectiveness of biomedical risk assessment as an aid for smoking cessation. Current evidence of lower quality does not however support the hypothesis that biomedical risk assessment increases smoking cessation in comparison with standard treatment. Only two studies were similar enough in term of recruitment, setting, and intervention to allow pooling of data and meta-analysis.

Passive smoking exposure in adults and dynamics of respiratory symptoms in a prospective multicenter cohort studies (SAPALDIA study)

Résumé Objectifs : Alors que de nombreuses études suggèrent que l'exposition au tabagisme passif représente un danger pour la santé des non-fumeurs, la plupart des études s'intéressant aux effets néfastes du tabagisme passif sur la santé respiratoire de sujets adultes étaient des études transversales. Les résultats d'études longitudinales restent rares et controversés. Le but de notre étude était de mesurer les effets d'une exposition antérieure au tabagisme passif sur l'évolution journalière de quatre catégories de symptômes respiratoires dans une étude journalière incluant des adultes n'ayant jamais fumé. Méthodes : Dans le cadre de l'étude SAPALDIA (Swiss study on air pollution and lung diseases in adults), nous avons mené une étude de cohorte prospective et multicentrique. 1421 adultes n'ayant jamais fumé étaient suivis durant deux ans sur la base de questionnaires journaliers remplis durant une à six périodes de quatre semaines répartis sur deux années (1992-1993). Nous avons ensuite déterminé le risque relatif (RR) de développer ou de s'amender de symptômes respiratoires en association avec une exposition antérieure au tabagisme passif. Résultats : Dans un échantillon d'adultes n'ayant jamais fumé, nous avons trouvé une association entre une exposition antérieure au tabagisme passif et une évolution péjorée de tous les symptômes respiratoires étudiés, montrant un risque relatif de 1.09 à 1.21 de développer les symptômes respiratoires, et un risque relatif de 0.91 à 0.83 de s'amender de ces symptômes. Une exposition au tabagisme passif sur la place de travail était associée à une diminution de la durée des intervalles libres sans symptômes bronchitiques (RR 1.33) et asthmatiques (RR 1.27), alors qu'une exposition uniquement en-dehors de la place de travail était associée avec un allongement de la durée des épisodes avec symptômes respiratoires des voies aériennes hautes ou basses (RR 0.78-0.77). Conclusion : Nos résultats suggèrent que l'exposition au tabagisme passif a des effets néfastes sur la dynamique journalière symptômes respiratoires, et que l'importance et le type d'effet sont influencés par le lieu d'exposition.

The effect of workplace smoking bans on heart rate variability and pulse wave velocity of non-smoking hospitality workers

OBJECTIVES: To investigate the effect of a change in second-hand smoke (SHS) exposure on heart rate variability (HRV) and pulse wave velocity (PWV), this study utilized a quasi-experimental setting when a smoking ban was introduced. METHODS: HRV, a quantitative marker of autonomic activity of the nervous system, and PWV, a marker of arterial stiffness, were measured in 55 non-smoking hospitality workers before and 3-12 months after a smoking ban and compared to a control group that did not experience an exposure change. SHS exposure was determined with a nicotine-specific badge and expressed as inhaled cigarette equivalents per day (CE/d). RESULTS: PWV and HRV parameters significantly changed in a dose-dependent manner in the intervention group as compared to the control group. A one CE/d decrease was associated with a 2.3 % (95 % CI 0.2-4.4; p = 0.031) higher root mean square of successive differences (RMSSD), a 5.7 % (95 % CI 0.9-10.2; p = 0.02) higher high-frequency component and a 0.72 % (95 % CI 0.40-1.05; p < 0.001) lower PWV. CONCLUSIONS: PWV and HRV significantly improved after introducing smoke-free workplaces indicating a decreased cardiovascular risk.

Tobacco and cannabis smoking cessation can lead to intoxication with clozapine or olanzapine

Plasma levels of clozapine and olanzapine are lower in smokers than in nonsmokers, which is mainly due to induction of cytochrome P4501A2 (CYP1A2) by some smoke constituents. Smoking cessation in patients treated with antipsychotic drugs that are CYP1A2 substrates may result in increased plasma levels of the drug and, consequently, in adverse drug effects. Two cases of patients who smoked tobacco and cannabis are reported. The first patient, who was receiving clozapine treatment, developed confusion after tobacco and cannabis smoking cessation, which was related to increased clozapine plasma levels. The second patient, who was receiving olanzapine treatment, showed important extrapyramidal motor symptoms after reducing his tobacco consumption. The clinical implication of these observations is that smoking patients treated with CYP1A2 substrate antipsychotics should regularly be monitored with regard to their smoking consumption in order to adjust doses in cases of a reduction or increase in smoking.

Chronic obstructive pulmonary disease in never-smoking animal farmers working inside confinement buildings

BACKGROUND: In animal farming, respiratory disease has been associated with indoor air contaminants and an excess in FEV1 decline. Our aim was to determine the characteristics and risk factors for chronic obstructive pulmonary disease (COPD) in never-smoking European farmers working inside animal confinement buildings. METHODS: A sample of participants in the European Farmers' Study was selected for a cross-sectional study assessing lung function and air contaminants. Dose-response relationships were assessed using logistic regression models. RESULTS: COPD was found in 18 of 105 farmers (45.1 SD 11.7 years) (17.1%); 8 cases (7.6%) with moderate and 3 cases (2.9%) with severe disease. Dust and endotoxin showed a dose-response relationship with COPD, with the highest prevalence of COPD in subjects with high dust (low=7.9%/high=31.6%) and endotoxin exposure (low=10.5%/high=20.0%). This association was statistically significant for dust in the multivariate analysis (OR 6.60, 95% CI 1.10-39.54). CONCLUSION: COPD in never-smoking animal farmers working inside confinement buildings is related to indoor dust exposure and may become severe. [Authors]

Cannabis and tobacco co-consumptions: can cannabis consumers quit cigarette smoking?

Purpose: To assess the relation between cannabis and tobacco consumption among adolescents in Switzerland and whether cannabis and tobacco co-users can quit cigarette smoking. Methods: Based on individual interviews and focus groups, 22 youths aged 15-20 discussed cannabis consumption behaviours. Twenty (14 males) were cannabis consumers - of which 18 also smoked tobacco and 2 quit tobacco smoking - and 2 were former cannabis consumers (both females and daily smokers). Data were transcribed verbatim and analyzed using Atlas.ti qualitative analysis software. Results: Among the co-consumers, 9 started with tobacco, 7 with cannabis, and 2 with both. The main consumption mode among all cannabis consumers is joints, while other ways of consuming such as food preparations and water pipes are rare and experimental. Joints always mix cannabis with tobacco for 3 reasons: to burn correctly, pure cannabis is too strong, and smoking cannabis alone is too expensive. Two cannabis consumers - one former tobacco smoker and one occasional tobacco smoker - consider rolling tobacco less addictive than cigarette tobacco alone, and hence use it in their joints. Overall cannabis is considered 'natural' and less harmful to health than tobacco. Thus, many users describe their wish, in the longer term, to quit tobacco consumption without excluding occasional cannabis consumption. Nonetheless, all coconsumers declare that they smoke cigarettes as a substitute for cannabis: For example, "If I don't have a joint, I need fags; if I don't have fags, I need joints; and if I don't have anything, I go crazy!" or "About 20 minutes after smoking a joint we feel like smoking something again, because in the joint there is pure tobacco without a filter as in cigarettes, and that creates a crazy dependency!". Finally, all co-consumers state that the consumption of one of the substances increases when trying to diminish the other: "A few months ago I stopped smoking joints for a month. Well I was smoking more than a pack [of cigarettes] a day." Similarly, the 2 former cannabis consumers increased their cigarette use since quitting cannabis. Conclusions: The majority of cannabis users co-consume tobacco as a way of compensating for one substance or the other. Using tobacco within joints implies that there is a risk that even occasional joints can revive nicotine addiction. Consequently, health professionals wishing to help adolescents in substance use cessation and prevention efforts should consider both substances in a global perspective. Sources of Support: Dept. of Public Health of the canton of Vaud.

Predictive Value of Readiness, Importance, and Confidence in Ability to Change Drinking and Smoking

Background: Visual analog scales (VAS) are used to assess readiness to changeconstructs, which are often considered critical for change.Objective: We studied whether 3 constructs -readiness to change, importance of changing and confidence inability to change- predict risk status 6 months later in 20 year-old men with either orboth of two behaviors: risky drinking and smoking. Methods: 577 participants in abrief intervention randomized trial were assessed at baseline and 6 months later onalcohol and tobacco consumption and with three 1-10 VAS (readiness, importance,confidence) for each behavior. For each behavior, we used one regression model foreach constructs. Models controlled for receipt of a brief intervention and used thelowest level (1-4) in each construct as the reference group (vs medium (5-7) and high(8-10) levels).Results: Among the 475 risky drinkers, mean (SD) readiness, importance and confidence to change drinking were 4.0 (3.1), 2.8 (2.2) and 7.2 (3.0).Readiness was not associated with being alcohol-risk free 6 months later (OR 1.3[0.7; 2.2] and 1.4 [0.8; 2.6] for medium and high readiness). High importance andhigh confidence were associated with being risk free (OR 0.9 [0.5; 1.8] and 2.9 [1.2;7.5] for medium and high importance; 2.1 [1.0;4.8] and 2.8 [1.5;5.6] for medium andhigh confidence). Among the 320 smokers, mean readiness, importance andconfidence to change smoking were 4.6 (2.6), 5.3 (2.6) and 5.9 (2.6). Neitherreadiness nor importance were associated with being smoking free (OR 2.1 [0.9; 4.7]and 2.1 [0.8; 5.8] for medium and high readiness; 1.4 [0.6; 3.4] and 2.1 [0.8; 5.4] formedium and high importance). High confidence was associated with being smokingfree (OR 2.2 [0.8;6.6] and 3.4 [1.2;9.8] for medium and high confidence).Conclusions: For drinking and smoking, high confidence in ability to change wasassociated -with similar magnitude- with a favorable outcome. This points to thevalue of confidence as an important predictor of successful change.

Pneumococcal penumonia presenting with septic shock: host-ant pathogen-related factors and outcomes

BACKGROUND: Host- and pathogen-related factors associated with septic shock in pneumococcal pneumonia are not well defined. The aim of this study was to identify risk factors for septic shock and to ascertain patient outcomes. Serotypes, genotypes and antibiotic resistance of isolated strains were also analysed. METHODS: Observational analysis of a prospective cohort of non-severely immunosuppressed hospitalised adults with pneumococcal pneumonia. Septic shock was defined as a systolic blood pressure of <90 mm Hg and peripheral hypoperfusion with the need for vasopressors for >4 h after fluid replacement. RESULTS: 1041 patients with pneumococcal pneumonia diagnosed by Gram stain and culture of appropriate samples and/or urine antigen test were documented, of whom 114 (10.9%) had septic shock at admission. After adjustment, independent risk factors for shock were current tobacco smoking (OR, 2.11; 95% CI, 1.02 to 4.34; p = 0.044), chronic corticosteroid treatment (OR, 4.45; 95% CI, 1.75 to 11.32; p = 0.002) and serotype 3 (OR, 2.24; 95% CI, 1.12 to 4.475; p = 0.022). No significant differences were found in genotypes and rates of antibiotic resistance. Compared with the remaining patients, patients with septic shock required mechanical ventilation more frequently (37% vs 4%; p<0.001) and had longer length of stay (11 vs 8 days; p<0.001). The early (10% vs 1%; p<0.001) and overall case fatality rates (25% vs 5%; p<0.001) were higher in patients with shock. CONCLUSIONS: Septic shock is a frequent complication of pneumococcal pneumonia and causes high morbidity and mortality. Current tobacco smoking, chronic corticosteroid treatment and infection caused by serotype 3 are independent risk factors for this complication.