Background and aims Behavioural smoking cessation trials have used comparators that vary considerably between trials. Although some previous meta‐analyses made attempts to account for variability in comparators, these relied on subsets of trials and incomplete data on comparators. This study aimed to estimate the relative effectiveness of (individual) smoking cessation interventions while accounting for variability in comparators using comprehensive data on experimental and comparator interventions. Methods A systematic review and meta‐regression was conducted including 172 randomised controlled trials with at least 6 months follow‐up and biochemically verified smoking cessation. Authors were contacted to obtain unpublished information. This information was coded in terms of active content and attributes of the study population and methods. Meta‐regression was used to create a model predicting smoking cessation outcomes. This model was used to re‐estimate intervention effects, as if all interventions have been evaluated against the same comparators. Outcome measures included log odds of smoking cessation for the meta‐regression models and smoking cessation differences and ratios to compare relative effectiveness. Results The meta‐regression model predicted smoking cessation rates well (pseudo R2 = 0.44). Standardising the comparator had substantial impact on conclusions regarding the (relative) effectiveness of trials and types of intervention. Compared with a ‘no support comparator’, self‐help was 1.33 times (95% CI = 1.16–1.49), brief physician advice 1.61 times (95% CI = 1.31–1.90), nurse individual counselling 1.76 times (95% CI = 1.62–1.90), psychologist individual counselling 2.04 times (95% CI = 1.95–2.15) and group psychologist interventions 2.06 times (95% CI = 1.92–2.20) more effective. Notably, more elaborate experimental interventions (e.g. psychologist counselling) were typically compared with more elaborate comparators, masking their effectiveness. Conclusions Comparator variability and underreporting of comparators obscures the interpretation, comparison and generalisability of behavioural smoking cessation trials. Comparator variability should, therefore, be taken into account when interpreting and synthesising evidence from trials. Otherwise, policymakers, practitioners and researchers may draw incorrect conclusions about the (cost) effectiveness of smoking cessation interventions and their constituent components. (PsycInfo Database Record (c) 2023 APA, all rights reserved)
BACKGROUND: Telephone services can provide information and support for smokers. Counselling may be provided proactively or offered reactively to callers to smoking cessation helplines.
OBJECTIVES: To evaluate the effect of telephone support to help smokers quit, including proactive or reactive counselling, or the provision of other information to smokers calling a helpline.
SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group Specialised Register, clinicaltrials.gov, and the ICTRP for studies of telephone counselling, using search terms including 'hotlines' or 'quitline' or 'helpline'. Date of the most recent search: May 2018.
SELECTION CRITERIA: Randomised or quasi-randomised controlled trials which offered proactive or reactive telephone counselling to smokers to assist smoking cessation.
DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. We pooled studies using a random-effects model and assessed statistical heterogeneity amongst subgroups of clinically comparable studies using the I2 statistic. In trials including smokers who did not call a quitline, we used meta-regression to investigate moderation of the effect of telephone counselling by the planned number of calls in the intervention, trial selection of participants that were motivated to quit, and the baseline support provided together with telephone counselling (either self-help only, brief face-to-face intervention, pharmacotherapy, or financial incentives).
MAIN RESULTS: We identified 104 trials including 111,653 participants that met the inclusion criteria. Participants were mostly adult smokers from the general population, but some studies included teenagers, pregnant women, and people with long-term or mental health conditions. Most trials (58.7%) were at high risk of bias, while 30.8% were at unclear risk, and only 11.5% were at low risk of bias for all domains assessed. Most studies (100/104) assessed proactive telephone counselling, as opposed to reactive forms.Among trials including smokers who contacted helplines (32,484 participants), quit rates were higher for smokers receiving multiple sessions of proactive counselling (risk ratio (RR) 1.38, 95% confidence interval (CI) 1.19 to 1.61; 14 trials, 32,484 participants; I2 = 72%) compared with a control condition providing self-help materials or brief counselling in a single call. Due to the substantial unexplained heterogeneity between studies, we downgraded the certainty of the evidence to moderate.In studies that recruited smokers who did not call a helpline, the provision of telephone counselling increased quit rates (RR 1.25, 95% CI 1.15 to 1.35; 65 trials, 41,233 participants; I2 = 52%). Due to the substantial unexplained heterogeneity between studies, we downgraded the certainty of the evidence to moderate. In subgroup analysis, we found no evidence that the effect of telephone counselling depended upon whether or not other interventions were provided (P = 0.21), no evidence that more intensive support was more effective than less intensive (P = 0.43), or that the effect of telephone support depended upon whether or not people were actively trying to quit smoking (P = 0.32). However, in meta-regression, telephone counselling was associated with greater effectiveness when provided as an adjunct to self-help written support (P < 0.01), or to a brief intervention from a health professional (P = 0.02); telephone counselling was less effective when provided as an adjunct to more intensive counselling. Further, telephone support was more effective for people who were motivated to try to quit smoking (P = 0.02). The findings from three additional trials of smokers who had not proactively called a helpline but were offered telephone counselling, found quit rates were higher in those offered three to five telephone calls compared to those offered just one call (RR 1.27, 95% CI 1.12 to 1.44; 2602 participants; I2 = 0%).
AUTHORS' CONCLUSIONS: There is moderate-certainty evidence that proactive telephone counselling aids smokers who seek help from quitlines, and moderate-certainty evidence that proactive telephone counselling increases quit rates in smokers in other settings. There is currently insufficient evidence to assess potential variations in effect from differences in the number of contacts, type or timing of telephone counselling, or when telephone counselling is provided as an adjunct to other smoking cessation therapies. Evidence was inconclusive on the effect of reactive telephone counselling, due to a limited number studies, which reflects the difficulty of studying this intervention.
BACKGROUND: Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.
OBJECTIVES: To determine the effectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions.
SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017.
SELECTION CRITERIA: Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months, except for those in pregnancy (where less than six months, these were excluded from the main analysis). We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing different types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews.
DATA COLLECTION AND ANALYSIS: Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.
MAIN RESULTS: We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 56 trials, 22,581 participants) for nicotine gum; 1.64 (95% CI 1.53 to 1.75, 51 trials, 25,754 participants) for nicotine patch; 1.52 (95% CI 1.32 to 1.74, 8 trials, 4439 participants) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials, 976 participants) for nicotine inhalator; and 2.02 (95% CI 1.49 to 2.73, 4 trials, 887 participants) for nicotine nasal spray. The effects were largely independent of the definition of abstinence, the intensity of additional support provided or the setting in which the NRT was offered. A subset of six trials conducted in pregnant women found a statistically significant benefit of NRT on abstinence close to the time of delivery (RR 1.32, 95% CI 1.04 to 1.69; 2129 participants); in the four trials that followed up participants post-partum the result was no longer statistically significant (RR 1.29, 95% CI 0.90 to 1.86; 1675 participants). Adverse events from using NRT were related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. Attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing and duration of symptoms. The odds ratio (OR) of chest pains or palpitations for any form of NRT relative to control was 1.88 (95% CI 1.37 to 2.57, 15 included and excluded trials, 11,074 participants). However, chest pains and palpitations were rare in both groups and serious adverse events were extremely rare.
AUTHORS' CONCLUSIONS: There is high-quality evidence that all of the licensed forms of NRT (gum, transdermal patch, nasal spray, inhalator and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50% to 60%, regardless of setting, and further research is very unlikely to change our confidence in the estimate of the effect. The relative effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. NRT often causes minor irritation of the site through which it is administered, and in rare cases can cause non-ischaemic chest pain and palpitations.
Background: Outpatient care facilities provide a variety of basic healthcare services to individuals who do not require hospitalisation or institutionalisation, and are usually the patient's first contact. The provision of outpatient care contributes to immediate and large gains in health status, and a large portion of total health expenditure goes to outpatient healthcare services. Payment method is one of the most important incentive methods applied by purchasers to guide the performance of outpatient care providers. Objectives: To assess the impact of different payment methods on the performance of outpatient care facilities and to analyse the differences in impact of payment methods in different settings. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), 2016, Issue 3, part of the Cochrane Library (searched 8 March 2016); MEDLINE, OvidSP (searched 8 March 2016); Embase, OvidSP (searched 24 April 2014); PubMed (NCBI) (searched 8 March 2016); Dissertations and Theses Database, ProQuest (searched 8 March 2016); Conference Proceedings Citation Index (ISI Web of Science) (searched 8 March 2016); IDEAS (searched 8 March 2016); EconLit, ProQuest (searched 8 March 2016); POPLINE, K4Health (searched 8 March 2016); China National Knowledge Infrastructure (searched 8 March 2016); Chinese Medicine Premier (searched 8 March 2016); OpenGrey (searched 8 March 2016); ClinicalTrials.gov, US National Institutes of Health (NIH) (searched 8 March 2016); World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (searched 8 March 2016); and the website of the World Bank (searched 8 March 2016). In addition, we searched the reference lists of included studies and carried out a citation search for the included studies via ISI Web of Science to find other potentially relevant studies. We also contacted authors of the main included studies regarding any further published or unpublished work. Selection criteria: Randomised trials, non-randomised trials, controlled before-after studies, interrupted time series, and repeated measures studies that compared different payment methods for outpatient health facilities. We defined outpatient care facilities in this review as facilities that provide health services to individuals who do not require hospitalisation or institutionalisation. We only included methods used to transfer funds from the purchaser of healthcare services to health facilities (including groups of individual professionals). These include global budgets, line-item budgets, capitation, fee-for-service (fixed and unconstrained), pay for performance, and mixed payment. The primary outcomes were service provision outcomes, patient outcomes, healthcare provider outcomes, costs for providers, and any adverse effects. Data collection and analysis: At least two review authors independently extracted data and assessed the risk of bias. We conducted a structured synthesis. We first categorised the comparisons and outcomes and then described the effects of different types of payment methods on different categories of outcomes. We used a fixed-effect model for meta-analysis within a study if a study included more than one indicator in the same category of outcomes. We used a random-effects model for meta-analysis across studies. If the data for meta-analysis were not available in some studies, we calculated the median and interquartile range. We reported the risk ratio (RR) for dichotomous outcomes and the relative change for continuous outcomes. Main results: We included 21 studies from Afghanistan, Burundi, China, Democratic Republic of Congo, Rwanda, Tanzania, the United Kingdom, and the United States of health facilities providing primary health care and mental health care. There were three kinds of payment comparisons. 1) Pay for performance (P4P) combined with some existing payment method (capitation or different kinds of input-based payment) compared to the existing payment method We included 18 studies in this comparison, however we did not include five studies in the effects analysis due to high risk of bias. From the 13 studies, we found that the extra P4P incentives probably slightly improved the health professionals' use of some tests and treatments (adjusted RR median = 1.095, range 1.01 to 1.17; moderate-certainty evidence), and probably led to little or no difference in adherence to quality assurance criteria (adjusted percentage change median = -1.345%, range -8.49% to 5.8%; moderate-certainty evidence). We also found that P4P incentives may have led to little or no difference in patients' utilisation of health services (adjusted RR median = 1.01, range 0.96 to 1.15; low-certainty evidence) and may have led to little or no difference in the control of blood pressure or cholesterol (adjusted RR = 1.01, range 0.98 to 1.04; low-certainty evidence). 2) Capitation combined with P4P compared to fee-for-service (FFS) One study found that compared with FFS, a capitated budget combined with payment based on providers' performance on antibiotic prescriptions and patient satisfaction probably slightly reduced antibiotic prescriptions in primary health facilities (adjusted RR 0.84, 95% confidence interval 0.74 to 0.96; moderate-certainty evidence). 3) Capitation compared to FFS Two studies compared capitation to FFS in mental health centres in the United States. Based on these studies, the effects of capitation compared to FFS on the utilisation and costs of services were uncertain (very low-certainty evidence). Authors' conclusions: Our review found that if policymakers intend to apply P4P incentives to pay health facilities providing outpatient services, this intervention will probably lead to a slight improvement in health professionals' use of tests or treatments, particularly for chronic diseases. However, it may lead to little or no improvement in patients' utilisation of health services or health outcomes. When considering using P4P to improve the performance of health facilities, policymakers should carefully consider each component of their P4P design, including the choice of performance measures, the performance target, payment frequency, if there will be additional funding, whether the payment level is sufficient to change the behaviours of health providers, and whether the payment to facilities will be allocated to individual professionals. Unfortunately, the studies included in this review did not help to inform those considerations. Well-designed comparisons of different payment methods for outpatient health facilities in low- and middle-income countries and studies directly comparing different designs (e.g. different payment levels) of the same payment method (e.g. P4P or FFS) are needed.
BACKGROUND: Both behavioural support (including brief advice and counselling) and pharmacotherapies (including nicotine replacement therapy (NRT), varenicline and bupropion) are effective in helping people to stop smoking. Combining both treatment approaches is recommended where possible, but the size of the treatment effect with different combinations and in different settings and populations is unclear.
OBJECTIVES: To assess the effect of combining behavioural support and medication to aid smoking cessation, compared to a minimal intervention or usual care, and to identify whether there are different effects depending on characteristics of the treatment setting, intervention, population treated, or take-up of treatment.
SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group Specialised Register in July 2015 for records with any mention of pharmacotherapy, including any type of NRT, bupropion, nortriptyline or varenicline.
SELECTION CRITERIA: Randomized or quasi-randomized controlled trials evaluating combinations of pharmacotherapy and behavioural support for smoking cessation, compared to a control receiving usual care or brief advice or less intensive behavioural support. We excluded trials recruiting only pregnant women, trials recruiting only adolescents, and trials with less than six months follow-up.
DATA COLLECTION AND ANALYSIS: Search results were prescreened by one author and inclusion or exclusion of potentially relevant trials was agreed by two authors. Data was extracted by one author and checked by another.The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) and 95% confidence interval (CI) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.
MAIN RESULTS: Fifty-three studies with a total of more than 25,000 participants met the inclusion criteria. A large proportion of studies recruited people in healthcare settings or with specific health needs. Most studies provided NRT. Behavioural support was typically provided by specialists in cessation counselling, who offered between four and eight contact sessions. The planned maximum duration of contact was typically more than 30 minutes but less than 300 minutes. Overall, studies were at low or unclear risk of bias, and findings were not sensitive to the exclusion of any of the six studies rated at high risk of bias in one domain. One large study (the Lung Health Study) contributed heterogeneity due to a substantially larger treatment effect than seen in other studies (RR 3.88, 95% CI 3.35 to 4.50). Since this study used a particularly intensive intervention which included extended availability of nicotine gum, multiple group sessions and long term maintenance and recycling contacts, the results may not be comparable with the interventions used in other studies, and hence it was not pooled in other analyses. Based on the remaining 52 studies (19,488 participants) there was high quality evidence (using GRADE) for a benefit of combined pharmacotherapy and behavioural treatment compared to usual care, brief advice or less intensive behavioural support (RR 1.83, 95% CI 1.68 to 1.98) with moderate statistical heterogeneity (I² = 36%).The pooled estimate for 43 trials that recruited participants in healthcare settings (RR 1.97, 95% CI 1.79 to 2.18) was higher than for eight trials with community-based recruitment (RR 1.53, 95% CI 1.33 to 1.76). Compared to the first version of the review, previous weak evidence of differences in other subgroup analyses has disappeared. We did not detect differences between subgroups defined by motivation to quit, treatment provider, number or duration of support sessions, or take-up of treatment.
AUTHORS' CONCLUSIONS: Interventions that combine pharmacotherapy and behavioural support increase smoking cessation success compared to a minimal intervention or usual care. Updating this review with an additional 12 studies (5,000 participants) did not materially change the effect estimate. Although trials differed in the details of their populations and interventions, we did not detect any factors that modified treatment effects apart from the recruitment setting. We did not find evidence from indirect comparisons that offering more intensive behavioural support was associated with larger treatment effects.
OBJECTIVE: The objective of the present review is to evaluate multicomponent/complex primary care (PC) interventions for their effectiveness in continuous smoking abstinence by adult smokers.
DESIGN: A systematic review of randomised and non-randomised controlled trials was undertaken.
ELIGIBILITY CRITERIA FOR INCLUDED STUDIES: Selected studies met the following criteria: evaluated effects of a multicomponent/complex intervention (with 2 or more intervention components) in achieving at least 6-month abstinence in adult smokers who visited a PC, biochemical confirmation of abstinence, intention-to-treat analysis and results published in English/Spanish.
METHODS: We followed PRISMA statement to report the review. We searched the following data sources: MEDLINE, Web of Science, Scopus (from inception to February 2014), 3 key journals and a tobacco research bulletin. The Scottish Intercollegiate Guidelines Network checklists were used to evaluate methodological quality. Data selection, evaluation and extraction were done independently, using a paired review approach. Owing to the heterogeneity of interventions in the studies included, a meta-analysis was not conducted.
RESULTS: Of 1147 references identified, 9 studies were selected (10 204 participants, up to 48 months of follow-up, acceptable methodological quality). Methodologies used were mainly individual or group sessions, telephone conversations, brochures or quit-smoking kits, medications and economic incentives for doctors and no-cost medications for smokers. Complex interventions achieved long-term continuous abstinence ranging from 7% to 40%. Behavioural interventions were effective and had a dose-response effect. Both nicotine replacement and bupropion therapy were safe and effective, with no observed differences.
CONCLUSIONS: Multicomponent/complex interventions in PC are effective and safe, appearing to achieve greater long-term continuous smoking cessation than usual care and counselling alone. Selected studies were heterogeneous and some had significant losses to follow-up. Our results show that smoking interventions should include more than one component and a strong follow-up of the patient to maximise results.
Objective Financial incentives are seen as one approach to encourage more systematic use of smoking cessation interventions by healthcare professionals. A systematic review was conducted to examine the evidence for this. Methods Medline, Embase, PsychINFO, Cochrane Library, ISI Web of Science and sources of grey literature were used as data sources. Studies were included if they reported the effects of any financial incentive provided to healthcare professionals to undertake smoking cessation-related activities. Data extraction and quality assessment for each study were conducted by one reviewer and checked by a second. A total of 18 studies were identified, consisting of 3 randomised controlled trials and 15 observational studies. All scored in the mid range for quality. In all, 8 studies examined smoking cessation activities alone and 10 studied the UK's Quality and Outcomes Framework targeting quality measures for chronic disease management including smoking recording or cessation activities. Five non-Quality and Outcomes Framework studies examined the effects of financial incentives on individual doctors and three examined effects on groups of healthcare professionals based in clinics and general practices. Most studies showed improvements in recording smoking status and smoking cessation advice. Five studies examined the impact of financial incentives on quit rates and longerterm abstinence and these showed mixed results. Conclusions Financial incentives appear to improve recording of smoking status, and increase the provision of cessation advice and referrals to stop smoking services. Currently there is not sufficient evidence to show that financial incentives lead to reductions in smoking rates.
BACKGROUND: Out-of-pocket payments can have a large impact on the demand for healthcare. They can be essential not only to decrease unnecessary service use, but also to encourage the use of particular preventive services provided free of charge or at a lower price. Moreover, out-of-pocket payments may increase the costs of unhealthy behaviour and provide incentives for a healthier lifestyle.
METHOD: This study systematically reviews empirical evidence on the effects of out-of-pocket payments on the use of preventive services and health-related lifestyle. All possible combinations of three key words 'prevention', 'patient payment' and 'health-related behaviour' were searched in PUBMED, ECONLITH, ECONPAPER and EMBASE. In total, 47 relevant publications were identified.
RESULTS: The results suggest that out-of-pocket payments can create a financial barrier and can decrease the use of preventive services and the uptake of preventive medications. A few studies (with contradicting empirical evidence) address the impact of cost sharing and reduced insurance coverage on a healthier lifestyle.
CONCLUSION: Although the great diversity of study designs (various indicators of out-of-pocket payments and preventive/health-related behaviour) makes it difficult to offer robust policy recommendations, our findings support calls to reconsider how preventive services should be financed. More research is needed to explore the actual impact of cost sharing on different aspects of health-related lifestyles, as well as to explain the role of other relevant determinants that could impact this relationship.
BACKGROUND: Pay-for-performance (P4P) intents to stimulate both more effective and more efficient health care delivery. To date, evidence on whether P4P itself is an efficient method has not been systematically analyzed.
OBJECTIVE: To identify and analyze the existing literature regarding economic evaluation of P4P.
DATA SOURCES: English, German, Spanish, and Turkish language literature were searched in the following databases: Business Source Complete, the Cochrane Library, Econlit, ISI web of knowledge, Medline (via PubMed), and PsycInfo (January 2000-April 2010).
STUDY SELECTION: Articles published in peer-reviewed journals and describing economic evaluations of P4P initiatives. Full economic evaluations, considering costs and consequences of the P4P intervention simultaneously, were the prime focus. Additionally, comparative partial evaluations were included if costs were described and the study allows for an assessment of consequences. Both experimental and observational studies were considered.
RESULTS: In total, nine studies could be identified. Three studies could be regarded as full economic evaluations, and six studies were classified as partial economic evaluations. Based on the full economic evaluations, P4P efficiency could not be demonstrated. Partial economic evaluations showed mixed results, but several flaws limit their significance. Ranges of costs and consequences were typically narrow, and programs differed considerably in design. Methodological quality assessment showed scores between 32% and 65%.
CONCLUSION: The results show that evidence on the efficiency of P4P is scarce and inconclusive. P4P efficiency could not be demonstrated. The small number and variability of included studies limit the strength of our conclusions. More research addressing P4P efficiency is needed.
Background and aims Behavioural smoking cessation trials have used comparators that vary considerably between trials. Although some previous meta‐analyses made attempts to account for variability in comparators, these relied on subsets of trials and incomplete data on comparators. This study aimed to estimate the relative effectiveness of (individual) smoking cessation interventions while accounting for variability in comparators using comprehensive data on experimental and comparator interventions. Methods A systematic review and meta‐regression was conducted including 172 randomised controlled trials with at least 6 months follow‐up and biochemically verified smoking cessation. Authors were contacted to obtain unpublished information. This information was coded in terms of active content and attributes of the study population and methods. Meta‐regression was used to create a model predicting smoking cessation outcomes. This model was used to re‐estimate intervention effects, as if all interventions have been evaluated against the same comparators. Outcome measures included log odds of smoking cessation for the meta‐regression models and smoking cessation differences and ratios to compare relative effectiveness. Results The meta‐regression model predicted smoking cessation rates well (pseudo R2 = 0.44). Standardising the comparator had substantial impact on conclusions regarding the (relative) effectiveness of trials and types of intervention. Compared with a ‘no support comparator’, self‐help was 1.33 times (95% CI = 1.16–1.49), brief physician advice 1.61 times (95% CI = 1.31–1.90), nurse individual counselling 1.76 times (95% CI = 1.62–1.90), psychologist individual counselling 2.04 times (95% CI = 1.95–2.15) and group psychologist interventions 2.06 times (95% CI = 1.92–2.20) more effective. Notably, more elaborate experimental interventions (e.g. psychologist counselling) were typically compared with more elaborate comparators, masking their effectiveness. Conclusions Comparator variability and underreporting of comparators obscures the interpretation, comparison and generalisability of behavioural smoking cessation trials. Comparator variability should, therefore, be taken into account when interpreting and synthesising evidence from trials. Otherwise, policymakers, practitioners and researchers may draw incorrect conclusions about the (cost) effectiveness of smoking cessation interventions and their constituent components. (PsycInfo Database Record (c) 2023 APA, all rights reserved)
Systematic Review Question»Systematic review of interventions
