Randomised controlled trial of tailored support to increase physical activity and reduce smoking in smokers not immediately ready to quit: protocol for the Trial of physical Activity-assisted Reduction of Smoking (TARS) Study

Effectiveness and cost-effectiveness of behavioural support for prolonged abstinence for smokers wishing to reduce but not quit: Randomised controlled trial of physical activity assisted reduction of smoking (TARS)

AIMS

For smokers unmotivated to quit, we assessed the effectiveness and cost-effectiveness of behavioural support to reduce smoking and increase physical activity on prolonged abstinence and related outcomes.

DESIGN

A multi-centred pragmatic two-arm parallel randomised controlled trial.

SETTING

Primary care and the community across four United Kingdom sites.

PARTICIPANTS

Nine hundred and fifteen adult smokers (55% female, 85% White), recruited via primary and secondary care and the community, who wished to reduce their smoking but not quit.

INTERVENTIONS

Participants were randomised to support as usual (SAU) (n = 458) versus multi-component community-based behavioural support (n = 457), involving up to eight weekly person-centred face-to-face or phone sessions with additional 6-week support for those wishing to quit.

MEASUREMENTS

Ideally, cessation follows smoking reduction so the primary pre-defined outcome was biochemically verified 6-month prolonged abstinence (from 3-9 months, with a secondary endpoint also considering abstinence between 9 and 15 months). Secondary outcomes included biochemically verified 12-month prolonged abstinence and point prevalent biochemically verified and self-reported abstinence, quit attempts, number of cigarettes smoked, pharmacological aids used, SF12, EQ-5D and moderate-to-vigorous physical activity (MVPA) at 3 and 9 months. Intervention costs were assessed for a cost-effectiveness analysis.

FINDINGS

Assuming missing data at follow-up implied continued smoking, nine (2.0%) intervention participants and four (0.9%) SAU participants achieved the primary outcome (adjusted odds ratio, 2.30; 95% confidence interval [CI] = 0.70-7.56, P = 0.169). At 3 and 9 months, the proportions self-reporting reducing cigarettes smoked from baseline by ≥50%, for intervention versus SAU, were 18.9% versus 10.5% (P = 0.009) and 14.4% versus 10% (P = 0.044), respectively. Mean difference in weekly MVPA at 3 months was 81.6 minutes in favour of the intervention group (95% CI = 28.75, 134.47: P = 0.003), but there was no significant difference at 9 months (23.70, 95% CI = -33.07, 80.47: P = 0.143). Changes in MVPA did not mediate changes in smoking outcomes. The intervention cost was £239.18 per person, with no evidence of cost-effectiveness.

CONCLUSIONS

For United Kingdom smokers wanting to reduce but not quit smoking, behavioural support to reduce smoking and increase physical activity improved some short-term smoking cessation and reduction outcomes and moderate-to-vigorous physical activity, but had no long-term effects on smoking cessation or physical activity.

Interventions for preventing weight gain after smoking cessation

BACKGROUND

Most people who stop smoking gain weight. This can discourage some people from making a quit attempt and risks offsetting some, but not all, of the health advantages of quitting. Interventions to prevent weight gain could improve health outcomes, but there is a concern that they may undermine quitting.

OBJECTIVES

To systematically review the effects of: (1) interventions targeting post-cessation weight gain on weight change and smoking cessation (referred to as 'Part 1') and (2) interventions designed to aid smoking cessation that plausibly affect post-cessation weight gain (referred to as 'Part 2').

SEARCH METHODS

Part 1 - We searched the Cochrane Tobacco Addiction Group's Specialized Register and CENTRAL; latest search 16 October 2020. Part 2 - We searched included studies in the following 'parent' Cochrane reviews: nicotine replacement therapy (NRT), antidepressants, nicotine receptor partial agonists, e-cigarettes, and exercise interventions for smoking cessation published in Issue 10, 2020 of the Cochrane Library. We updated register searches for the review of nicotine receptor partial agonists.

SELECTION CRITERIA

Part 1 - trials of interventions that targeted post-cessation weight gain and had measured weight at any follow-up point or smoking cessation, or both, six or more months after quit day. Part 2 - trials included in the selected parent Cochrane reviews reporting weight change at any time point.

DATA COLLECTION AND ANALYSIS

Screening and data extraction followed standard Cochrane methods. Change in weight was expressed as difference in weight change from baseline to follow-up between trial arms and was reported only in people abstinent from smoking. Abstinence from smoking was expressed as a risk ratio (RR). Where appropriate, we performed meta-analysis using the inverse variance method for weight, and Mantel-Haenszel method for smoking.

MAIN RESULTS

Part 1: We include 37 completed studies; 21 are new to this update. We judged five studies to be at low risk of bias, 17 to be at unclear risk and the remainder at high risk.  An intermittent very low calorie diet (VLCD) comprising full meal replacement provided free of charge and accompanied by intensive dietitian support significantly reduced weight gain at end of treatment compared with education on how to avoid weight gain (mean difference (MD) -3.70 kg, 95% confidence interval (CI) -4.82 to -2.58; 1 study, 121 participants), but there was no evidence of benefit at 12 months (MD -1.30 kg, 95% CI -3.49 to 0.89; 1 study, 62 participants). The VLCD increased the chances of abstinence at 12 months (RR 1.73, 95% CI 1.10 to 2.73; 1 study, 287 participants). However, a second study  found that no-one completed the VLCD intervention or achieved abstinence. Interventions aimed at increasing acceptance of weight gain reported mixed effects at end of treatment, 6 months and 12 months with confidence intervals including both increases and decreases in weight gain compared with no advice or health education. Due to high heterogeneity, we did not combine the data. These interventions increased quit rates at 6 months (RR 1.42, 95% CI 1.03 to 1.96; 4 studies, 619 participants; I² = 21%), but there was no evidence at 12 months (RR 1.25, 95% CI 0.76 to 2.06; 2 studies, 496 participants; I² = 26%). Some pharmacological interventions tested for limiting post-cessation weight gain (PCWG) reduced weight gain at the end of treatment (dexfenfluramine, phenylpropanolamine, naltrexone). The effects of ephedrine and caffeine combined, lorcaserin, and chromium were too imprecise to give useful estimates of treatment effects. There was very low-certainty evidence that personalized weight management support reduced weight gain at end of treatment (MD -1.11 kg, 95% CI -1.93 to -0.29; 3 studies, 121 participants; I² = 0%), but no evidence in the longer-term 12 months (MD -0.44 kg, 95% CI -2.34 to 1.46; 4 studies, 530 participants; I² = 41%). There was low to very low-certainty evidence that detailed weight management education without personalized assessment, planning and feedback did not reduce weight gain and may have reduced smoking cessation rates (12 months: MD -0.21 kg, 95% CI -2.28 to 1.86; 2 studies, 61 participants; I² = 0%; RR for smoking cessation 0.66, 95% CI 0.48 to 0.90; 2 studies, 522 participants; I² = 0%). Part 2: We include 83 completed studies, 27 of which are new to this update. There was low certainty that exercise interventions led to minimal or no weight reduction compared with standard care at end of treatment (MD -0.25 kg, 95% CI -0.78 to 0.29; 4 studies, 404 participants; I² = 0%). However, weight was reduced at 12 months (MD -2.07 kg, 95% CI -3.78 to -0.36; 3 studies, 182 participants; I² = 0%). Both bupropion and fluoxetine limited weight gain at end of treatment (bupropion MD -1.01 kg, 95% CI -1.35 to -0.67; 10 studies, 1098 participants; I² = 3%); (fluoxetine MD -1.01 kg, 95% CI -1.49 to -0.53; 2 studies, 144 participants; I² = 38%; low- and very low-certainty evidence, respectively). There was no evidence of benefit at 12 months for bupropion, but estimates were imprecise (bupropion MD -0.26 kg, 95% CI -1.31 to 0.78; 7 studies, 471 participants; I² = 0%). No studies of fluoxetine provided data at 12 months. There was moderate-certainty that NRT reduced weight at end of treatment (MD -0.52 kg, 95% CI -0.99 to -0.05; 21 studies, 2784 participants; I² = 81%) and moderate-certainty that the effect may be similar at 12 months (MD -0.37 kg, 95% CI -0.86 to 0.11; 17 studies, 1463 participants; I² = 0%), although the estimates are too imprecise to assess long-term benefit. There was mixed evidence of the effect of varenicline on weight, with high-certainty evidence that weight change was very modestly lower at the end of treatment (MD -0.23 kg, 95% CI -0.53 to 0.06; 14 studies, 2566 participants; I² = 32%); a low-certainty estimate gave an imprecise estimate of higher weight at 12 months (MD 1.05 kg, 95% CI -0.58 to 2.69; 3 studies, 237 participants; I² = 0%).

AUTHORS' CONCLUSIONS

Overall, there is no intervention for which there is moderate certainty of a clinically useful effect on long-term weight gain. There is also no moderate- or high-certainty evidence that interventions designed to limit weight gain reduce the chances of people achieving abstinence from smoking.

Factors Affecting the Intention to Modify Lifestyle in the Cardiovascular Disease Risk Group in Korea

This study aimed to identify people at risk of cardiovascular diseases (CVD) using the Framingham risk score (FRS) and to examine their willingness to modify their lifestyle. A descriptive correlational study with 1229 participants, aged 30-74 years, without cardiovascular or cerebrovascular diseases who visited a health examination center in South Korea was conducted. Of 1229 participants, 455 were identified as high risk for CVD with an FRS of 10 or higher. A logistic regression analysis confirmed age, sex, muscle training, and weekly drinking frequency as predictors of intention to quit smoking; age, smoking, and waist to height ratio (WHtR) as predictors of intention to quit drinking; sex and WHtR as predictors of intention to engage in physical exercise; and hypertension and body mass index as predictors of intention of muscle training. People at high risk for CVD lack willingness to modify their lifestyle, and aggressive, customized intervention is needed to promote lifestyle modification.