High risk strategy in smoking cessation is feasible on a population-based level. The Inter99 study

Associations between noticing public health education campaigns about cannabis and risk perceptions in the northern Canadian territories: a cross-sectional study

This study investigated whether noticing cannabis education campaigns was associated with increased cannabis risk perceptions in Canada's three territories following non-medical cannabis legalization. Data were from the Cannabis Policy Study in the Territories, including 2452 participants, age ≥16 years residing in Yukon, Northwest Territories and Nunavut. Poisson regression with robust standard errors were used to estimate associations between noticing cannabis education campaigns and moderate to very high risk perceptions of daily cannabis smoking, vaping, edible use and exposure to second-hand cannabis smoke, adjusting for sociodemographic characteristics and cannabis-use frequency. Results were compared with associations with risk perceptions of daily alcohol consumption and cigarette smoking, not included in cannabis education campaigns. Interactions were examined between noticing education campaigns and age group and cannabis-use frequency. Cannabis education campaigns were noticed by 40.4% of respondents, with lower awareness among those with lower education and income. Noticing campaigns was associated with higher risk perceptions of daily cannabis smoking [adjusted risk ratio (RRadj) = 1.09, 95% confidence interval (CI): 1.02-1.16] and vaping (RRadj = 1.09, 95%CI: 1.02-1.16). Significant interactions were not found with age group or cannabis-use frequency. Findings are consistent with modest effects of cannabis education campaigns. Approaches are needed to increase reach of cannabis education campaigns, including among groups with lower education and income.

Development and initial validation of the cannabis-related psychosis risk literacy scale (CPRL): a multinational psychometric study

BACKGROUND

Public education efforts to address and reduce potential harms from cannabis use in Arab countries are either slow or inexistent, and do not follow the steadily increasing trends of cannabis use in Arab youth. Several decades of research on substance use, it can be suggested that being aware of, and knowing about, psychosis risk related to cannabis can at least limit the consumption of the substance. Motivated by a lack of measures specifically designed to measure literacy about cannabis-related psychosis risk in younger populations, and based on an extensive literature review, we aimed to create and validate a new self-report scale to assess the construct, the Cannabis-related Psychosis Risk Literacy Scale (CPRL), in the Arabic language.

METHOD

A cross-sectional study was carried-out during the period from September 2022 to June 2023, enrolling 1855 university students (mean age of 23.26 ± 4.96, 75.6% females) from three Arab countries (Egypt, Kuwait and Tunisia).

RESULTS

Starting from an initial pool of 20 items, both Exploratory Factor Analysis and Confirmatory Factor Analysis suggested that the remaining 8 items loaded into a single factor. The scale demonstrated good internal consistency, with both McDonald omega and Cronbach's alpha values exceeding 0.7 (omega = 0.85 / alpha = 0.85). The CPRL showed measurement invariance across gender and country at the configural, metric, and scalar levels. Concurrent validity of the CPRL was established by correlations with less favourable attitudes towards cannabis (r = -.14; p <.001). In addition, higher literacy levels were found in students who never used cannabis compared to lifetime users (4.18 ± 1.55 vs. 3.44 ± 1.20, t(1853) = 8.152, p <.001).

CONCLUSION

The newly developed CPRL scale offers a valid and reliable instrument for assessing and better understanding literacy about cannabis-related psychosis risk among Arabic-speaking young adults. We believe that this new scale is suitable as a screening tool of literacy, as an instrument for measuring the effect of public education interventions aimed at promoting cannabis-related psychosis risk literacy among young people, and as a research tool to facilitate future studies on the topic with a wider application.

Non-linear interaction between physical activity and polygenic risk score of body mass index in Danish and Russian populations

Body mass index (BMI) is a highly heritable polygenic trait. It is also affected by various environmental and behavioral risk factors. We used a BMI polygenic risk score (PRS) to study the interplay between the genetic and environmental factors defining BMI. First, we generated a BMI PRS that explained more variance than a BMI genetic risk score (GRS), which was using only genome-wide significant BMI-associated variants (R² = 13.1% compared to 6.1%). Second, we analyzed interactions between BMI PRS and seven environmental factors. We found a significant interaction between physical activity and BMI PRS, even when the well-known effect of the FTO region was excluded from the PRS, using a small dataset of 6,179 samples. Third, we stratified the study population into two risk groups using BMI PRS. The top 22% of the studied populations were included in a high PRS risk group. Engagement in self-reported physical activity was associated with a 1.66 kg/m² decrease in BMI in this group, compared to a 0.84 kg/m² decrease in BMI in the rest of the population. Our results (i) confirm that genetic background strongly affects adult BMI in the general population, (ii) show a non-linear interaction between BMI genetics and physical activity, and (iii) provide a standardized framework for future gene-environment interaction analyses.

Cannabis health knowledge and risk perceptions among Canadian youth and young adults

Abstract

Background

Although recreational cannabis is now legal in Canada, little empirical evidence exists regarding young Canadians’ cannabis literacy, cannabis-related risk perceptions, and risk of different forms of cannabis or the effect that public health education may have on these perceptions. The present study sought to address these knowledge gaps to examine health knowledge and risk perceptions associated with cannabis use.

Methods

An online survey was conducted with a national sample (N = 870) of Canadians aged 16 to 30 years in October 2017 using a commercial panel. The study examined young Canadians’ awareness of negative health effects related to cannabis, evaluation of known risks, and risk perceptions of different forms of administration.

Results

Most respondents were aware of a cannabis-related physical health effect (78.0%). Approximately one-third reported having been exposed to public health messaging about cannabis; digital media was reported most frequently. Compared to never users, ever users were less likely to report general likelihood of addiction (p < 0.001) and harm to mental health (p < 0.001). Approximately one-quarter of past 3-month cannabis users reported they were at least “a little” addicted. Respondents who reported using a particular form of cannabis self-administration (e.g., edibles, smokables) were less likely to perceive harm than those who did not use each form (p < 0.001).

Conclusions

The current study is among the first to measure the knowledge and perceptions of risks of Canadian youth about cannabis. The study, conducted in the time immediately preceding legalization, may serve as a reference point for future studies examining changes in cannabis knowledge and risk perceptions. This will be important in addressing the need for monitoring and enhancing public awareness of the impact and potential harms of this newly legalized substance.

Factors influencing doctors' counselling on patients' lifestyle habits: a cohort study

Background

Lifestyle changes are important for prevention and treatment of many common diseases, and doctors have an important role in the lifestyle counselling of patients. It is important to know more about factors influencing lifestyle counselling.

Aim

To investigate the frequency of counselling about physical activity compared to that about alcohol habits; the impact of doctors' own physical activity and alcohol habits on patient counselling about these lifestyle dimensions; and whether perceived mastery of clinical work or vulnerable personality have a confounding or moderating effect on these associations.

Design & setting

In this nationwide cohort survey, a total of 978 doctors in Norway were surveyed by postal questionnaires in 1993/94 and 2014. The response rate was 562/978 (57%).

Method

The outcome variables were questions on frequency of asking about alcohol and exercise habits. Explanatory variables were questions on doctors' own exercise habits, drinking habits (using Alcohol Use Disorders Identification Test [AUDIT]), perceived mastery of clinical work, vulnerable personality, and specialty. Associations were studied by linear regression analysis.

Results

Of the 526 responders, 307 (58%) reported asking usually/often about exercise habits, while n = 140/524 (27%) usually/often asked about alcohol habits. A doctor's own physical activity level was associated with frequency of asking about physical activity (unstandardised regression coefficient [B] = 0.07; 95% confidence intervals [CI] = 0.01 to 0.13). There were no significant associations between doctors' own lifestyle habits and counselling on alcohol habits. Doctors with low levels of vulnerability asked more frequently about physical activity, regardless of their own physical activity habits (F = 2.41, P = 0.048).

Conclusion

Doctors' own lifestyles influenced their preventive counselling about physical activity, but not about alcohol. Vulnerability moderated these effects, indicating the importance of early interventions to help doctors with a vulnerable personality to handle negative criticism from patients.

Harms of cigarette smoking: call to increase knowledge among children

Although the major burden of disease caused by smoking is observed in the adult population, two-third of smokers start before the age of 18 years. Reducing the number of young smokers could lead to marked improvements to the health of the UK population and save billions of pounds in National Health Service finances. However, very little is known about what makes children decide to not smoke or to quit early. We believe that increased awareness of the health risks associated with smoking will reduce smoking uptake among children. This study identifies a significant lack of knowledge among children aged 11-17 years at two London secondary schools and potentially identifies an area for improving our antismoking programmes. Although 80% of pupils cited lung cancer as being a smoking-related disease, very few other conditions could be recalled. We must do all we can to reduce smoking uptake in children. Understanding their baseline knowledge is the first step towards addressing the deficits in our current antismoking programmes.

Group behaviour therapy programmes for smoking cessation

BACKGROUND

Group therapy offers individuals the opportunity to learn behavioural techniques for smoking cessation, and to provide each other with mutual support.

OBJECTIVES

To determine the effect of group-delivered behavioural interventions in achieving long-term smoking cessation.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialized Register, using the terms 'behavior therapy', 'cognitive therapy', 'psychotherapy' or 'group therapy', in May 2016.

SELECTION CRITERIA

Randomized trials that compared group therapy with self-help, individual counselling, another intervention or no intervention (including usual care or a waiting-list control). We also considered trials that compared more than one group programme. We included those trials with a minimum of two group meetings, and follow-up of smoking status at least six months after the start of the programme. We excluded trials in which group therapy was provided to both active therapy and placebo arms of trials of pharmacotherapies, unless they had a factorial design.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data in duplicate on the participants, the interventions provided to the groups and the controls, including programme length, intensity and main components, the outcome measures, method of randomization, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months follow-up in participants smoking at baseline. We used the most rigorous definition of abstinence in each trial, and biochemically-validated rates where available. We analysed participants lost to follow-up as continuing smokers. We expressed effects as a risk ratio for cessation. Where possible, we performed meta-analysis using a fixed-effect (Mantel-Haenszel) model. We assessed the quality of evidence within each study and comparison, using the Cochrane 'Risk of bias' tool and GRADE criteria.

MAIN RESULTS

Sixty-six trials met our inclusion criteria for one or more of the comparisons in the review. Thirteen trials compared a group programme with a self-help programme; there was an increase in cessation with the use of a group programme (N = 4395, risk ratio (RR) 1.88, 95% confidence interval (CI) 1.52 to 2.33, I2 = 0%). We judged the GRADE quality of evidence to be moderate, downgraded due to there being few studies at low risk of bias. Fourteen trials compared a group programme with brief support from a health care provider. There was a small increase in cessation (N = 7286, RR 1.22, 95% CI 1.03 to 1.43, I2 = 59%). We judged the GRADE quality of evidence to be low, downgraded due to inconsistency in addition to risk of bias. There was also low quality evidence of benefit of a group programme compared to no-intervention controls, (9 trials, N = 1098, RR 2.60, 95% CI 1.80 to 3.76 I2 = 55%). We did not detect evidence that group therapy was more effective than a similar intensity of individual counselling (6 trials, N = 980, RR 0.99, 95% CI 0.76 to 1.28, I2 = 9%). Programmes which included components for increasing cognitive and behavioural skills were not shown to be more effective than same-length or shorter programmes without these components.

AUTHORS' CONCLUSIONS

Group therapy is better for helping people stop smoking than self-help, and other less intensive interventions. There is not enough evidence to evaluate whether groups are more effective, or cost-effective, than intensive individual counselling. There is not enough evidence to support the use of particular psychological components in a programme beyond the support and skills training normally included.

Risk scoring for the primary prevention of cardiovascular disease

BACKGROUND

The current paradigm for cardiovascular disease (CVD) emphasises absolute risk assessment to guide treatment decisions in primary prevention. Although the derivation and validation of multivariable risk assessment tools, or CVD risk scores, have attracted considerable attention, their effect on clinical outcomes is uncertain.

OBJECTIVES

To assess the effects of evaluating and providing CVD risk scores in adults without prevalent CVD on cardiovascular outcomes, risk factor levels, preventive medication prescribing, and health behaviours.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (2016, Issue 2), MEDLINE Ovid (1946 to March week 1 2016), Embase (embase.com) (1974 to 15 March 2016), and Conference Proceedings Citation Index-Science (CPCI-S) (1990 to 15 March 2016). We imposed no language restrictions. We searched clinical trial registers in March 2016 and handsearched reference lists of primary studies to identify additional reports.

SELECTION CRITERIA

We included randomised and quasi-randomised trials comparing the systematic provision of CVD risk scores by a clinician, healthcare professional, or healthcare system compared with usual care (i.e. no systematic provision of CVD risk scores) in adults without CVD.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected studies, extracted data, and evaluated study quality. We used the Cochrane 'Risk of bias' tool to assess study limitations. The primary outcomes were: CVD events, change in CVD risk factor levels (total cholesterol, systolic blood pressure, and multivariable CVD risk), and adverse events. Secondary outcomes included: lipid-lowering and antihypertensive medication prescribing in higher-risk people. We calculated risk ratios (RR) for dichotomous data and mean differences (MD) or standardised mean differences (SMD) for continuous data using 95% confidence intervals. We used a fixed-effects model when heterogeneity (I²) was at least 50% and a random-effects model for substantial heterogeneity (I² > 50%). We evaluated the quality of evidence using the GRADE framework.

MAIN RESULTS

We identified 41 randomised controlled trials (RCTs) involving 194,035 participants from 6422 reports. We assessed studies as having high or unclear risk of bias across multiple domains. Low-quality evidence evidence suggests that providing CVD risk scores may have little or no effect on CVD events compared with usual care (5.4% versus 5.3%; RR 1.01, 95% confidence interval (CI) 0.95 to 1.08; I² = 25%; 3 trials, N = 99,070). Providing CVD risk scores may reduce CVD risk factor levels by a small amount compared with usual care. Providing CVD risk scores reduced total cholesterol (MD -0.10 mmol/L, 95% CI -0.20 to 0.00; I² = 94%; 12 trials, N = 20,437, low-quality evidence), systolic blood pressure (MD -2.77 mmHg, 95% CI -4.16 to -1.38; I² = 93%; 16 trials, N = 32,954, low-quality evidence), and multivariable CVD risk (SMD -0.21, 95% CI -0.39 to -0.02; I² = 94%; 9 trials, N = 9549, low-quality evidence). Providing CVD risk scores may reduce adverse events compared with usual care, but results were imprecise (1.9% versus 2.7%; RR 0.72, 95% CI 0.49 to 1.04; I² = 0%; 4 trials, N = 4630, low-quality evidence). Compared with usual care, providing CVD risk scores may increase new or intensified lipid-lowering medications (15.7% versus 10.7%; RR 1.47, 95% CI 1.15 to 1.87; I² = 40%; 11 trials, N = 14,175, low-quality evidence) and increase new or increased antihypertensive medications (17.2% versus 11.4%; RR 1.51, 95% CI 1.08 to 2.11; I² = 53%; 8 trials, N = 13,255, low-quality evidence).

AUTHORS' CONCLUSIONS

There is uncertainty whether current strategies for providing CVD risk scores affect CVD events. Providing CVD risk scores may slightly reduce CVD risk factor levels and may increase preventive medication prescribing in higher-risk people without evidence of harm. There were multiple study limitations in the identified studies and substantial heterogeneity in the interventions, outcomes, and analyses, so readers should interpret results with caution. New models for implementing and evaluating CVD risk scores in adequately powered studies are needed to define the role of applying CVD risk scores in primary CVD prevention.

Genetic determinants of serum vitamin B12 and their relation to body mass index

Lower serum vitamin B12 levels have been related to adverse metabolic health profiles, including adiposity. We used a Mendelian randomization design to test whether this relation might be causal. We included two Danish population-based studies (ntotal = 9311). Linear regression was used to test for associations between (1) serum vitamin B12 levels and body mass index (BMI), (2) genetic variants and serum vitamin B12 levels, and (3) genetic variants and BMI. The effect of a genetically determined decrease in serum vitamin B12 on BMI was estimated by instrumental variable regression. Decreased serum vitamin B12 associated with increased BMI (P < 1 × 10-4). A genetic risk score based on eight vitamin B12 associated variants associated strongly with serum vitamin B12 (P < 2 × 10-43), but not with BMI (P = 0.91). Instrumental variable regression showed that a 20% decrease in serum vitamin B12 was associated with a 0.09 kg/m2 (95% CI 0.05; 0.13) increase in BMI (P = 3 × 10-5), whereas a genetically induced 20% decrease in serum vitamin B12 had no effect on BMI [-0.03 (95% CI -0.22; 0.16) kg/m2] (P = 0.74). Nevertheless, the strongest serum vitamin B12 variant, FUT2 rs602662, which was excluded from the B12 genetic risk score due to potential pleiotropic effects, showed a per allele effect of 0.15 kg/m2 (95% CI 0.01; 0.32) on BMI (P = 0.03). This association was accentuated including two German cohorts (ntotal = 5050), with a combined effect of 0.19 kg/m2 (95% CI 0.08; 0.30) (P = 4 × 10-4). We found no support for a causal role of decreased serum vitamin B12 levels in obesity. However, our study suggests that FUT2, through its regulation of the cross-talk between gut microbes and the human host, might explain a part of the observational association between serum vitamin B12 and BMI.

Increasing insulin resistance accentuates the effect of triglyceride-associated loci on serum triglycerides during 5 years

Blood concentrations of triglycerides are influenced by genetic factors as well as a number of environmental factors, including adiposity and glucose homeostasis. The aim was to investigate the association between a serum triglyceride weighted genetic risk score (wGRS) and changes in fasting serum triglyceride level over 5 years and to test whether the effect of the wGRS was modified by 5 year changes of adiposity, insulin resistance, and lifestyle factors. A total of 3,474 nondiabetic individuals from the Danish Inter99 cohort participated in both the baseline and 5 year follow-up physical examinations and had information on the wGRS comprising 39 genetic variants. In a linear regression model adjusted for age, sex, and baseline serum triglyceride, the wGRS was associated with increased serum triglyceride levels over 5 years [per allele effect = 1.3% (1.0-1.6%); P = 1.0 × 10-17]. This triglyceride-increasing effect of the wGRS interacted with changes in insulin resistance (Pinteraction = 1.5 × 10-6). This interaction indicated that the effect of the wGRS was stronger in individuals who became more insulin resistant over 5 years. In conclusion, our findings suggest that increased genetic risk load is associated with a larger increase in fasting serum triglyceride levels in nondiabetic individuals during 5 years of follow-up. This effect of the wGRS is accentuated by increasing insulin resistance.

Combination Therapies for Smoking Cessation: A Hierarchical Bayesian Meta-Analysis

CONTEXT

Treatment guidelines recommend the use of combination therapies for smoking cessation, particularly behavioral therapy (BT) as an adjunct to pharmacotherapy. However, these guidelines rely on previous reviews with important limitations. This study's objective was to evaluate the efficacy of combination therapies compared with monotherapies, using the most rigorous data available.

EVIDENCE ACQUISITION

A systematic review and meta-analysis of RCTs of pharmacotherapies, BTs, or both were conducted. The Cochrane Library, Embase, PsycINFO, and PubMed databases were systematically searched from inception to July 2015. Inclusion was restricted to RCTs reporting biochemically validated abstinence at 12 months. Direct and indirect comparisons were made in 2015 between therapies using hierarchical Bayesian models.

EVIDENCE SYNTHESIS

The search identified 123 RCTs meeting inclusion criteria (60,774 participants), and data from 115 (57,851 participants) were meta-analyzed. Varenicline with BT increased abstinence more than other combinations of a pharmacotherapy with BT (varenicline versus bupropion: OR=1.56, 95% credible interval [CrI]=1.07, 2.34; varenicline versus nicotine patch: OR=1.65, 95% CrI=1.10, 2.51; varenicline versus short-acting nicotine-replacement therapies: OR=1.68, 95% CrI=1.15, 2.53). Adding BT to any pharmacotherapy compared with pharmacotherapy alone was inconclusive, owing to wide CrIs (OR=1.17, CrI=0.60, 2.12). Nicotine patch with short-acting nicotine-replacement therapy appears safe and increases abstinence versus nicotine-replacement monotherapy (OR=1.63, CrI=1.06, 3.03). Data are limited concerning other pharmacotherapy combinations and their safety and tolerability.

CONCLUSIONS

Evidence suggests that combination therapy benefits may be less than previously thought. Combined with BT, varenicline increases abstinence more than other pharmacotherapy with BT combinations.

Is self-selection the main driver of positive interpretations of general health checks? The Inter99 randomized trial

OBJECTIVE

To investigate if the lower mortality among participants of a health check followed by lifestyle intervention of high risk persons is explained by self-selection.

METHODS

All persons residing in the study area (Copenhagen; Denmark) were randomized to intervention (n=11,629) or control group (n=47,987). Persons in the intervention group were invited for a health check and individual lifestyle counselling. At baseline, 52.5% participated. Differences between participants and control group in 10-year all-cause and disease specific mortality was assessed. In survival analyses we controlled for socio-demography and mental and physical health.

RESULTS

Mortality rates were highest among non-participants and lowest among participants in the intervention group, whereas mortality rates of controls were approximately the average of those of participants and non-participants. In adjusted analyses the difference in both all-cause mortality (HR 0.73, 95% CI 0.62-0.85) and disease specific mortality was diminished between participants and controls, and turning insignificant as regard cancer mortality. In total, 39% of the lower mortality among participants in the intervention group was explained by self-selection according to socio-demography and health.

CONCLUSION

A substantial part of the lower mortality among participants in a preventive health check can be explained by confounding. The remaining lower mortality is most probably due to residual confounding, as the lower mortality was seen both for lifestyle related and non-lifestyle related diseases.

The long-term effect of a population-based life-style intervention on smoking and alcohol consumption. The Inter99 Study--a randomized controlled trial

AIMS

To examine whether improvements in smoking and alcohol consumption throughout the 5-year course of a population-based multi-factorial life-style intervention were sustained 5 years after its discontinuation.

DESIGN

Population-based randomized controlled trial.

SETTING

Suburbs of Copenhagen, Denmark.

PARTICIPANTS

A total of 9415 people aged 30-60 years were randomized to an intervention group (n = 6091) and an assessment-only control group (n = 3324).

INTERVENTION

All participants in the intervention group received screening, risk assessment and individual life-style counselling; participants at high risk of ischaemic heart disease-according to pre-specified criteria-were also offered group-based counselling.

MEASUREMENTS

Self-reported point abstinence from smoking as well as changes in the average alcohol consumption per week and binge drinking in the past week from baseline to 10-year follow-up were investigated using random-effects modelling.

FINDINGS

At 10-year follow up, people in the intervention group reported a higher smoking abstinence rate [odds ratio (OR) = 1.84, 95% confidence interval (CI) = 1.02-3.33, P = 0.043] and a greater reduction in binge drinking (net change = -0.08 days with binge drinking in the last week, 95% CI = -0.16 to -0.01, P = 0.028) than in the control group. There were no detectable long-term intervention effects on the average alcohol consumption per week.

CONCLUSIONS

A population-based multi-factorial life-style intervention of 5 years' duration in Denmark had sustained beneficial effects on smoking abstinence and binge drinking 5 years after its discontinuation.

Interactions of Lipid Genetic Risk Scores With Estimates of Metabolic Health in a Danish Population

Background—

There are several well-established lifestyle factors influencing dyslipidemia and currently; 157 genetic susceptibility loci have been reported to be associated with serum lipid levels at genome-wide statistical significance. However, the interplay between lifestyle risk factors and these susceptibility loci has not been fully elucidated. We tested whether genetic risk scores (GRS) of lipid-associated single nucleotide polymorphisms associate with fasting serum lipid traits and whether the effects are modulated by lifestyle factors or estimates of metabolic health.

Methods and Results—

The single nucleotide polymorphisms were genotyped in 2 Danish cohorts: inter99 (n=5961) for discovery analyses and Health2006 (n=2565) for replication. On the basis of published effect sizes of single nucleotide polymorphisms associated with circulating fasting levels of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, or triglyceride, 4 weighted GRS were constructed. In a cross-sectional design, we investigated whether the effect of these weighted GRSs on lipid levels were modulated by diet, alcohol consumption, physical activity, and smoking or the individual metabolic health status as estimated from body mass index, waist circumference, and insulin resistance assessed using homeostasis model assessment of insulin resistance. All 4 lipid weighted GRSs associated strongly with their respective trait (from P =3.3×10 –69 to P =1.1×10 –123 ). We found interactions between the triglyceride weighted GRS and body mass index and waist circumference on fasting triglyceride levels in Inter99 and replicated these findings in Health2006 ( P interaction =9.8×10 –5 and 2.0×10 –5 , respectively, in combined analysis).

Conclusions—

Our findings suggest that individuals who are obese may be more susceptible to the cumulative genetic burden of triglyceride single nucleotide polymorphisms. Therefore, it is suggested that especially these genetically at-risk individuals may benefit more from targeted interventions aiming at obesity prevention.

Effect of screening and lifestyle counselling on incidence of ischaemic heart disease in general population: Inter99 randomised trial

OBJECTIVE

To investigate the effect of systematic screening for risk factors for ischaemic heart disease followed by repeated lifestyle counselling on the 10 year development of ischaemic heart disease at a population level.

DESIGN

Randomised controlled community based trial.

SETTING

Suburbs of Copenhagen, Denmark.

PARTICIPANTS

59,616 people aged 30-60 years randomised with different age and sex randomisation ratios to an intervention group (n = 11,629) and a control group (n = 47,987).

INTERVENTION

The intervention group was invited for screening, risk assessment, and lifestyle counselling up to four times over a five year period. All participants with an unhealthy lifestyle had individually tailored lifestyle counselling at all visits (at baseline and after one and three years); those at high risk of ischaemic heart disease, according to predefined criteria, were furthermore offered six sessions of group based lifestyle counselling on smoking cessation, diet, and physical activity. After five years all were invited for a final counselling session. Participants were referred to their general practitioner for medical treatment, if relevant. The control group was not invited for screening.

MAIN OUTCOME MEASURES

The primary outcome measure was incidence of ischaemic heart disease in the intervention group compared with the control group. Secondary outcome measures were stroke, combined events (ischaemic heart disease, stroke, or both), and mortality.

RESULTS

6091 (52.4%) people in the intervention group participated at baseline. Among 5978 people eligible at five year follow-up (59 died and 54 emigrated), 4028 (67.4%) attended. A total of 3163 people died in the 10 year follow-up period. Among 58,308 without a history of ischaemic heart disease at baseline, 2782 developed ischaemic heart disease. Among 58,940 without a history of stroke at baseline, 1726 developed stroke. No significant difference was seen between the intervention and control groups in the primary end point (hazard ratio for ischaemic heart disease 1.03, 95% confidence interval 0.94 to 1.13) or in the secondary endpoints (stroke 0.98, 0.87 to 1.11; combined endpoint 1.01, 0.93 to 1.09; total mortality 1.00, 0.91 to 1.09).

CONCLUSION

A community based, individually tailored intervention programme with screening for risk of ischaemic heart disease and repeated lifestyle intervention over five years had no effect on ischaemic heart disease, stroke, or mortality at the population level after 10 years.Trial registration Clinical trials NCT00289237.

Equity impact of European individual-level smoking cessation interventions to reduce smoking in adults: a systematic review

BACKGROUND

Smoking is the leading cause of health inequalities in Europe. Adults from lower socioeconomic status (SES) groups are more likely to smoke and less likely to quit than adults from higher SES groups. Smoking cessation support is an important element of tobacco control; however, the equity impact of individual-level cessation support is uncertain.

METHODS

Systematic review of individual-level smoking cessation interventions delivered in European countries, reporting a smoking cessation outcome (quit) in adults of lower compared with higher SES. Equity impact was assessed as positive (reduced inequality), neutral (no difference by SES), negative (increased inequality) or unclear.

RESULTS

Twenty-nine studies were included using different types of support: behavioural and pharmacological (17); behavioural only (11), including specialist (5), brief advice (1), mass media (2), text-based (1) and Internet-based (2); and pharmacological only (1). The distribution of equity effects on quitting was 10 neutral, 18 negative and 1 unclear. Two national studies of UK National Health Service (NHS) stop-smoking services showed overall positive equity impact on smoking prevalence. The evidence suggests that UK NHS services that target low-SES smokers achieve a relatively higher service uptake among low-SES smokers, which can compensate for their lower quit rates.

CONCLUSIONS

Untargeted smoking cessation interventions in Europe may have contributed to reducing adult smoking but are, on balance, likely to have increased inequalities in smoking. However, UK NHS stop-smoking services appear to reduce inequalities in smoking through increased relative reach through targeting services to low-SES smokers. More research is needed to strengthen the evidence-base for reducing smoking inequalities.

The effect of GWAS identified BMI loci on changes in body weight among middle-aged Danes during a five-year period

OBJECTIVE

Genome-wide association studies have identified genetic variants associating with BMI, however, it is un-clarified whether the same variants also influence body weight fluctuations.

METHODS

Among 3,982 adult individuals that attended both a baseline and a five-year follow-up examination in the Danish Inter99 intervention study, a genetic risk score (GRS) was constructed based on 30 BMI variants to address whether it is associated with body weight changes. Moreover, it was examined whether the effect of lifestyle changes was modulated by the GRS.

RESULTS

The GRS associated strongly with baseline body weight, with a per risk allele increase of 0.45 (0.33-0.58) kg (P = 2.7 × 10(-12) ), corresponding to a body weight difference of 3.41 (2.21-4.60) kg comparing the highest (≥ 30 risk alleles) and lowest (≤ 26 risk alleles) risk allele tertile. No association was observed with changes in body weight during the five years. Changes in lifestyle, including physical activity, diet and smoking habits associated strongly with body weight changes, however, no interactions with the GRS was observed.

CONCLUSION

The GRS associated with body weight cross-sectionally, but not with changes over a five-year period. Body weight changes were influenced by lifestyle changes, however, independently of the GRS.

Genetic risk score of 46 type 2 diabetes risk variants associates with changes in plasma glucose and estimates of pancreatic β-cell function over 5 years of follow-up

More than 40 genetic risk variants for type 2 diabetes have been validated. We aimed to test whether a genetic risk score associates with the incidence of type 2 diabetes and with 5-year changes in glycemic traits and whether the effects were modulated by changes in BMI and lifestyle. The Inter99 study population was genotyped for 46 variants, and a genetic risk score was constructed. During a median follow-up of 11 years, 327 of 5,850 individuals developed diabetes. Physical examinations and oral glucose tolerance tests were performed at baseline and after 5 years (n = 3,727). The risk of incident type 2 diabetes was increased with a hazard ratio of 1.06 (95% CI 1.03-1.08) per risk allele. While the population in general had improved glucose regulation during the 5-year follow-up period, each additional allele in the genetic risk score was associated with a relative increase in fasting, 30-min, and 120-min plasma glucose values and a relative decrease in measures of β-cell function over the 5-year period, whereas indices of insulin sensitivity were unaffected. The effect of the genetic risk score on 5-year changes in fasting plasma glucose was stronger in individuals who increased their BMI. In conclusion, a genetic risk score based on 46 variants associated strongly with incident type 2 diabetes and 5-year changes in plasma glucose and β-cell function. Individuals who gain weight may be more susceptible to the cumulative impact of type 2 diabetes risk variants on fasting plasma glucose.

The cost effectiveness of telephone counselling to aid smoking cessation in Denmark: a modelling study

AIM

To assess the cost-effectiveness of the Danish smoking cessation telephone service "quitline".

METHODS

The study was based on the number of quitline callers in 2005. The outcome was measured as costs per life year saved (LYS) based on the assessment in 2001 of continued abstinence over a 12-month period (19.0%) and point prevalence of abstinence at 12 months of follow up (29.7%), respectively. The costs per LYS are estimated as the annual running costs of reactive telephone counselling service divided by the total number of LYS, which has been estimated as the difference between current smokers' and ex-smokers' life expectancies according to age group and gender based on Danish smoking proportions, relative risks of smoking-related mortality of all causes, and standard life tables.

RESULTS

A total of 511 ex-smokers have been estimated to gain 2172 life years based on continued abstinence over 12 months. Using the point prevalence abstinence at 12 months, 799 ex-smokers are estimated to gain 3394 life years. Discounting LYS at 3% p.a., the costs per LYS are €213 for ex-smokers with continued abstinence and €137 for ex-smokers with point prevalence abstinence. The sensitivity analysis for a worst-case scenario indicates that the costs per LYS are €1199. For comparison the average costs per LYS of smoking cessation interventions in other Danish settings are €1592 (95% CI €1547-1636).

CONCLUSIONS

The Danish reactive telephone counselling to aid smoking cessation appears to be cost-effective in comparison with other Danish smoking cessation interventions.

Positive impact of Australian 'blindness' tobacco warning labels: findings from the ITC four country survey

BACKGROUND

Smokers with greater knowledge of the health effects of smoking are more likely to quit and remain abstinent. Australia has communicated the causal association of smoking and blindness since the late 1990s. In March 2007, Australia became the first country to include a pictorial warning label on cigarette packages with the message that smoking causes blindness. The current study tested the hypothesis that the introduction of this warning label increased smokers' knowledge of this important health effect.

METHODS

Six waves of the International Tobacco Control Four Country Survey were conducted, as a telephone survey of 17,472 adult smokers in Australia, Canada, United Kingdom and the United States, with three waves before and three waves after the blindness health warning was introduced in Australia. The survey measured adult smokers' knowledge that smoking causes blindness.

RESULTS

Australian smokers were significantly more likely to report that smoking causes blindness, compared to Canadian, UK and US smokers, where there were neither health campaigns nor health warnings labels about blindness. After the introduction of the blindness warning, Australian smokers were more likely than before the blindness warning to report that they know that smoking causes blindness (62 versus 49 per cent; OR = 1.68, 95% CI: 1.03, 2.76, p = 0.04). In Australia, smokers aged over 55 years were less likely than those aged 18 to 24 to report that smoking causes blindness (OR = 0.43; 95% CI: 0.29, 0.62, p < 0.001).

CONCLUSION

While more smokers report that smoking causes blindness in Australia compared to other countries, which have not had national social marketing campaigns, further gains in knowledge were found after pictorial warning labels were introduced in Australia. Findings suggest there is still a need to educate the public about the causal association of smoking and blindness. More education may be needed to redress the knowledge gap in older Australian smokers as the incidence of age-related macular degeneration increases with age.

The potential of smoking cessation programmes and a smoking ban in public places: Comparing gain in life expectancy and cost effectiveness

Background: Interventions aimed at reducing the number of smokers are generally believed to be cost effective. However as the cost of the interventions should be paid up front whereas the gains in life years only appear in the future – the budgetary consequences might be a barrier to implementing such interventions. Aims: The aim of the present paper was to assess the long-term cost effectiveness as well as the short-term (10 years) budget consequences of cessation programmes and a smoking ban in enclosed public places. Methods: We develop a population-based Markov model capable of analyzing both interventions and assess long-term costs effectiveness as well as short-term budgetary consequences and outcome gains. The smoking cessation programme model was based on data from the Danish National Smoking Cessation Database (SCDB), while the model of the smoking ban was based on effect estimates found in the literature. Results: On a population level the effect of a smoking ban has the largest potential compared with the effect of smoking cessation programmes. Our results suggest that smoking cessation programmes are cost saving and generate life-years, whereas the costs per life-year gained by a smoking ban are 40,645 to 64,462 DKK (100 DKK = €13.4). These results are conservative as they do not include the healthcare cost saving related to reduced passive smoking. Conclusions: Our results indicate that smoking cessation programmes and a smoking ban in enclosed public places both in the short term and the long term are cost-effective strategies compared with the status quo.

Socioeconomic position, stage of lung cancer and time between referral and diagnosis in Denmark, 2001-2008

Introduction:

We investigated the association between socioeconomic position, stage at diagnosis, and length of period between referral and diagnosis in a nationwide cohort of lung cancer patients.

Methods:

Through the Danish Lung Cancer Register, we identified 18 103 persons diagnosed with lung cancer (small cell and non-small cell) in Denmark, 2001–2008, and obtained information on socioeconomic position and comorbidity from nationwide administrative registries. The odds ratio (OR) for a diagnosis of advanced-stage lung cancer (stages IIIB–IV) and for a diagnosis >28 days after referral were analysed by multivariate logistic regression models.

Results:

The adjusted OR for advanced-stage lung cancer was reduced among persons with higher education (OR, 0.92; 95% confidence interval (CI), 0.84–0.99), was increased in persons living alone (OR, 1.06; 95% CI, 1.01–1.13) and decreased stepwise with increasing comorbidity. Higher education was associated with a reduced OR for >28 days between referral and diagnosis as was high income in early-stage patients. Male gender, age and severe comorbidity were associated with increased ORs in advanced-stage patients.

Interpretation:

Differences by socioeconomic position in stage at diagnosis and in the period between referral and diagnosis indicate that vulnerable patients presenting with lung cancer symptoms require special attention.

Knowledge about the relationship between smoking and blindness in Canada, the United States, the United Kingdom, and Australia: results from the International Tobacco Control Four-Country Project

PURPOSE

Smoking is causally associated with certain prevalent visually impairing eye diseases, including age-related macular degeneration and cataract. Studies have found that people are afraid of "going blind" and may be motivated to quit smoking if they know that vision loss is associated with smoking behavior.

METHODS

A random-digit dialed telephone survey was used to measure health knowledge of adult smokers in Canada (n = 2,765), the United States (n = 3,178), the United Kingdom (n = 2,767), and Australia (n = 2,623) as part of the International Tobacco Control Four-Country Project.

RESULTS

A low proportion of smokers from Canada (13.0%), the United States (9.5%), and the United Kingdom (9.7%) believed that smoking can cause blindness. In contrast, 47.2% of Australian smokers believed that smoking causes blindness. Australia was the only country during the sampling period to have national awareness campaigns about smoking and its effects on eye health.

CONCLUSION

These findings point to the need across countries to educate the public on this important consequence of smoking. There is an opportunity for the public health and eye health communities to work to educate the public about the impacts smoking has on eye health to improve quit rates and help discourage people from starting to smoke.

Stage-based interventions for smoking cessation

BACKGROUND

The transtheoretical model is the most widely known of several stage-based theories of behaviour. It proposes that smokers move through a discrete series of motivational stages before they quit successfully. These are precontemplation (no thoughts of quitting), contemplation (thinking about quitting), preparation (planning to quit in the next 30 days), action (quitting successfully for up to six months), and maintenance (no smoking for more than six months). According to this influential model, interventions which help people to stop smoking should be tailored to their stage of readiness to quit, and are designed to move them forward through subsequent stages to eventual success. People in the preparation and action stages of quitting would require different types of support from those in precontemplation or contemplation.

OBJECTIVES

Our primary objective was to test the effectiveness of stage-based interventions in helping smokers to quit.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('stage* of change', 'transtheoretical model*', 'trans-theoretical model*, 'precaution adoption model*', 'health action model', 'processes of change questionnaire*', 'readiness to change', 'tailor*') and 'smoking' in the title or abstract, or as keywords. The latest search was in August 2010.

SELECTION CRITERIA

We included randomized controlled trials, which compared stage-based interventions with non-stage-based controls, with 'usual care' or with assessment only. We excluded trials which did not report a minimum follow-up period of six months from start of treatment, and those which measured stage of change but did not modify their intervention in the light of it.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the participants, the dose and duration of intervention, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up.The main outcome was abstinence from smoking for at least six months. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where reported. Where appropriate we performed meta-analysis to estimate a pooled risk ratio, using the Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We found 41 trials (>33,000 participants) which met our inclusion criteria. Four trials, which directly compared the same intervention in stage-based and standard versions, found no clear advantage for the staging component. Stage-based versus standard self-help materials (two trials) gave a relative risk (RR) of 0.93 (95% CI 0.62 to 1.39). Stage-based versus standard counselling (two trials) gave a relative risk of 1.00 (95% CI 0.82 to 1.22). Six trials of stage-based self-help systems versus any standard self-help support demonstrated a benefit for the staged groups, with an RR of 1.27 (95% CI 1.01 to 1.59). Twelve trials comparing stage-based self help with 'usual care' or assessment-only gave an RR of 1.32 (95% CI 1.17 to 1.48). Thirteen trials of stage-based individual counselling versus any control condition gave an RR of 1.24 (95% CI 1.08 to 1.42). These findings are consistent with the proven effectiveness of these interventions in their non-stage-based versions. The evidence was unclear for telephone counselling, interactive computer programmes or training of doctors or lay supporters. This uncertainty may be due in part to smaller numbers of trials.

AUTHORS' CONCLUSIONS

Based on four trials using direct comparisons, stage-based self-help interventions (expert systems and/or tailored materials) and individual counselling were neither more nor less effective than their non-stage-based equivalents. Thirty-one trials of stage-based self help or counselling interventions versus any control condition demonstrated levels of effectiveness which were comparable with their non-stage-based counterparts. Providing these forms of practical support to those trying to quit appears to be more productive than not intervening. However, the additional value of adapting the intervention to the smoker's stage of change is uncertain. The evidence is not clear for other types of staged intervention, including telephone counselling, interactive computer programmes and training of physicians or lay supporters. The evidence does not support the restriction of quitting advice and encouragement only to those smokers perceived to be in the preparation and action stages.

Combined analyses of 20 common obesity susceptibility variants

OBJECTIVE

Genome-wide association studies and linkage studies have identified 20 validated genetic variants associated with obesity and/or related phenotypes. The variants are common, and they individually exhibit small-to-modest effect sizes.

RESEARCH DESIGN AND METHODS

In this study we investigate the combined effect of these variants and their ability to discriminate between normal weight and overweight/obese individuals. We applied receiver operating characteristics (ROC) curves, and estimated the area under the ROC curve (AUC) as a measure of the discriminatory ability. The analyses were performed cross-sectionally in the population-based Inter99 cohort where 1,725 normal weight, 1,519 overweight, and 681 obese individuals were successfully genotyped for all 20 variants.

RESULTS

When combining all variants, the 10% of the study participants who carried more than 22 risk-alleles showed a significant increase in probability of being both overweight with an odds ratio of 2.00 (1.47-2.72), P = 4.0 x 10(-5), and obese with an OR of 2.62 (1.76-3.92), P = 6.4 x 10(-7), compared with the 10% of the study participants who carried less than 14 risk-alleles. Discrimination ability for overweight and obesity, using the 20 single nucleotide polymorphisms (SNPs), was determined to AUCs of 0.53 and 0.58, respectively. When combining SNP data with conventional nongenetic risk factors of obesity, the discrimination ability increased to 0.64 for overweight and 0.69 for obesity. The latter is significantly higher (P < 0.001) than for the nongenetic factors alone (AUC = 0.67).

CONCLUSIONS

The discriminative value of the 20 validated common obesity variants is at present time sparse and too weak for clinical utility, however, they add to increase the discrimination ability of conventional nongenetic risk factors.

Five years of lifestyle intervention improved self-reported mental and physical health in a general population: the Inter99 study

INTRODUCTION

Self-reported health has been shown to predict mortality. We lack knowledge on whether a lifestyle intervention can improve self-reported mental and physical health in a general population.

METHODS

Inter99, Denmark (1999-2006) is a randomised population-based intervention study. We screened for ischemic heart disease and repeatedly offered advice and assistance to obtain a healthier lifestyle. Health related quality of life was measured by Short Form 12 (SF-12); completed by 9322 at baseline and 7719 at five-year follow-up. In linear mixed models we investigated the effect of the intervention on self-reported health over time.

RESULTS

At baseline men had higher physical health-component scores (PCS) than women. Living with a partner, being employed, and being healthy was associated with high PCS. The mental health-component scores (MCS) showed the same socio-demographic differences, except that MCS increased with age. Significantly fewer participants in the intervention groups had decreased their PCS and MCS compared with the control group. Adjusted multilevel analyses confirmed that the intervention significantly improved physical- (p=0.008) and mental health (p<0.001) over time compared with the control group.

CONCLUSION

Screening for ischemic heart disease and offering lifestyle intervention had a significantly beneficial effect on mental and physical self-reported health in the long term in a general population.

The relationship between lifestyle and self-reported health in a general population: the Inter99 study

OBJECTIVES

The aim of this paper is to describe the relationship between smoking status, dietary habits, physical activity and alcohol intake, and mental and physical self-reported health in a general population.

MEASURES

A large population-based study Inter99, Copenhagen, Denmark, 1999-2006. Self-reported health-related quality of life was measured by Short Form 12 (SF-12). Mental and physical health component scores were computed.

RESULTS

At baseline, SF-12 was completed by 6305 (92.3%) participants in the intervention groups, and 3017 (72.4%) persons in the control group. In cross-sectional analyses, persons with an unhealthy lifestyle reported significantly worse physical and mental health than persons with a healthier lifestyle. In longitudinal data, using adjusted multivariate analyses (N=3,084), we found an association between increased physical activity at five-year follow-up and improvement in physical health ( odds ratio=2.30 (95% confidence interval=1.7-3.2)) in the high-intensity intervention group. Improvement in mental health was associated with a much healthier diet at 5-year follow-up than at baseline ( odds ratio=1.68 (95% confidence interval=1.1-2.5)).

CONCLUSIONS

This study describes the negative relationship between unhealthy lifestyle and self-reported mental and physical health in a general population. Also, it shows the impact of improvements in lifestyle on self-reported health in a general population, which has not been investigated before.

The impact of a population-based multi-factorial lifestyle intervention on alcohol intake: the Inter99 study

PURPOSE

To investigate the effect of screening and five years of multi-factorial lifestyle intervention on changes in alcohol intake in a general population.

METHODS

The study was a pre-randomized intervention study on lifestyle, Inter99 (1999-2006), Copenhagen, Denmark. Participants in the intervention group (n=6 091) had at baseline a medical health examination and a face-to-face lifestyle counselling. Individuals at high risk of ischemic heart disease were repeatedly offered both individual and group-based counselling. The control group (n=3 324) was followed by questionnaires. Alcohol intake was measured by questionnaires. Changes were analysed by multilevel analyses.

RESULTS

Binge drinking decreased both in men and women at three and five-year follow-ups (men: five-year: net-change:-0.13; p=0.03; women: five-year: net-change:-0.08; p=0.04). Furthermore, in women the ratio between wine and total alcohol was increased compared with the control group at five-year follow-up (net-change: 0.04; p<0.01). In men with a high intake of alcohol (>21 drinks per week) the effect on total alcohol intake was maintained at five-year follow-up (net-change: -3.7; p=0.01). No significant effects were found in women on total alcohol intake.

CONCLUSION

Multi-factorial lifestyle intervention, including low intensity alcohol intervention, improved long-term alcohol habits in a general population.

Development of a type 2 diabetes risk model from a panel of serum biomarkers from the Inter99 cohort

OBJECTIVE

The purpose of this study was to develop a model for assessing the 5-year risk of developing type 2 diabetes from a panel of 64 circulating candidate biomarkers.

RESEARCH DESIGN AND METHODS

Subjects were selected from the Inter99 cohort, a longitudinal population-based study of approximately 6,600 Danes in a nested case-control design with the primary outcome of 5-year conversion to type 2 diabetes. Nondiabetic subjects, aged >or=39 years, with BMI >or=25 kg/m(2) at baseline were selected. Baseline fasting serum samples from 160 individuals who developed type 2 diabetes and from 472 who did not were tested. An ultrasensitive immunoassay was used to measure of 58 candidate biomarkers in multiple diabetes-associated pathways, along with six routine clinical variables. Statistical learning methods and permutation testing were used to select the most informative biomarkers. Risk model performance was estimated using a validated bootstrap bias-correction procedure.

RESULTS

A model using six biomarkers (adiponectin, C-reactive protein, ferritin, interleukin-2 receptor A, glucose, and insulin) was developed for assessing an individual's 5-year risk of developing type 2 diabetes. This model has a bootstrap-estimated area under the curve of 0.76, which is greater than that for A1C, fasting plasma glucose, fasting serum insulin, BMI, sex-adjusted waist circumference, a model using fasting glucose and insulin, and a noninvasive clinical model.

CONCLUSIONS

A model incorporating six circulating biomarkers provides an objective and quantitative estimate of the 5-year risk of developing type 2 diabetes, performs better than single risk indicators and a noninvasive clinical model, and provides better stratification than fasting plasma glucose alone.

Five-year change in physical activity is associated with changes in cardiovascular disease risk factors: the Inter99 study

OBJECTIVE

To evaluate whether five-year changes in self-reported physical activity level were associated with changes in waist circumference, weight, serum lipids and blood pressure.

METHODS

In the Inter99 study (1999-2006) in Copenhagen, Denmark, 4039 men and women (30-60 years) answered questions on lifestyle and provided blood samples and anthropometric measures at baseline and after five years. Multiple regression analyses were performed with five-year value of each cardiovascular biomarker as outcome and change in physical activity level as explanatory variable.

RESULTS

Approximately 50% of the study population were men (n=2023). Change in physical activity level was inversely associated with change in weight (p<0.0001), waist (p<0.0001), diastolic blood pressure (p=0.04), total cholesterol (p=0.006), LDL (p=0.007), triglycerides (p=0.02) and with a composite risk score "the Copenhagen risk score" (p<0.0001), and positively associated with HDL in men (p=0.01).

CONCLUSION

Five-year changes in physical activity level were significantly associated with relevant changes in weight, waist circumference, diastolic BP and serum lipids in a population-based cohort of adult men and women. Change in physical activity level induced a significant change in HDL concentration in men only. Women's use of hormone replacement therapy may partly explain this gender difference.

Group behaviour therapy programmes for smoking cessation

BACKGROUND

Group therapy offers individuals the opportunity to learn behavioural techniques for smoking cessation, and to provide each other with mutual support.

OBJECTIVES

We aimed to determine the effects of smoking cessation programmes delivered in a group format compared to self-help materials, or to no intervention; to compare the effectiveness of group therapy and individual counselling; and to determine the effect of adding group therapy to advice from a health professional or to nicotine replacement. We also aimed to determine whether specific components increased the effectiveness of group therapy. We aimed to determine the rate at which offers of group therapy are taken up.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group Trials Register, with additional searches of MEDLINE and PsycINFO, including the terms behavior therapy, cognitive therapy, psychotherapy or group therapy, in January 2005.

SELECTION CRITERIA

We considered randomized trials that compared group therapy with self help, individual counselling, another intervention or no intervention (including usual care or a waiting list control). We also considered trials that compared more than one group programme. We included those trials with a minimum of two group meetings, and follow up of smoking status at least six months after the start of the programme. We excluded trials in which group therapy was provided to both active therapy and placebo arms of trials of pharmacotherapies, unless they had a factorial design.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the participants, the interventions provided to the groups and the controls, including programme length, intensity and main components, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least six months follow up in patients smoking at baseline. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates where available. Subjects lost to follow up were analyzed as continuing smokers. Where possible, we performed meta-analysis using a fixed-effects (Mantel-Haenszel) model.

MAIN RESULTS

A total of 55 trials met inclusion criteria for one or more of the comparisons in the review. Sixteen studies compared a group programme with a self-help programme. There was an increase in cessation with the use of a group programme (N = 4395, odds ratio (OR) 2.04, 95% confidence interval (CI) 1.60 to 2.60). Group programmes were more effective than no intervention controls (seven trials, N = 815, OR 2.17, 95% CI 1.37 to 3.45). There was no evidence that group therapy was more effective than a similar intensity of individual counselling. There was limited evidence that the addition of group therapy to other forms of treatment, such as advice from a health professional or nicotine replacement, produced extra benefit. There was variation in the extent to which those offered group therapy accepted the treatment. There was limited evidence that programmes which included components for increasing cognitive and behavioural skills and avoiding relapse were more effective than same length or shorter programmes without these components. This analysis was sensitive to the way in which one study with multiple conditions was included. We did not find an effect of manipulating the social interactions between participants in a group programme on outcome.

AUTHORS' CONCLUSIONS

Group therapy is better for helping people stop smoking than self help, and other less intensive interventions. There is not enough evidence to evaluate whether groups are more effective, or cost-effective, than intensive individual counselling. There is not enough evidence to support the use of particular psychological components in a programme beyond the support and skills training normally included.