Effect of financial voucher incentives provided with UK stop smoking services on the cessation of smoking in pregnant women (CPIT III): pragmatic, multicentre, single blinded, phase 3, randomised controlled trial

Effect of 3 months and 12 months of financial incentives on 12-month postpartum smoking cessation maintenance: A randomized controlled trial

BACKGROUND AND AIMS

Offering financial incentives is effective for smoking cessation during pregnancy. We tested the effectiveness of financial incentives for maintaining postpartum cessation, comparing 12-month and 3-month incentives with each other and with usual care (UC).

DESIGN, SETTING AND PARTICIPANTS

This study was a pragmatic, multi-centre, three-arm randomized controlled trial involving four English, National Health Service, stop smoking services. A total of 462 postpartum women (aged ≥ 16 years) took part, who stopped smoking during pregnancy with financial incentives, validated as abstinent from smoking at end of pregnancy or early postpartum.

INTERVENTIONS

Interventions comprised (i) UC; (ii) UC plus up to £60 of financial voucher incentives offered to participants and £60 offered to an optional significant-other supporter, over 3 months postpartum, contingent upon validated abstinence ('3-month incentives'); or (iii) UC plus '3-month incentives' plus £180 of vouchers offered to participants over 9 months postpartum, contingent upon abstinence ('12-month incentives').

MEASUREMENTS

Primary outcome: biochemically validated abstinence at 1 year postpartum. To adjust for testing all comparisons between groups with equal precision, P < 0.017 was necessary for significance.

SECONDARY OUTCOMES

self-reported and validated abstinence at 3 months postpartum; self-reported abstinence at 1 year postpartum.

FINDINGS

Primary outcome ascertainment: abstinence was 39.6% (63/159) 12 months incentives, 21.4% (33/154) 3 months incentives and 28.2% (42/149) UC. Adjusted odds ratios [95% confidence interval (CI)] = 12-month versus 3-month incentives OR = 2.41 (95% CI = 1.46-3.96), P = 0.001; 12 months versus UC 1.67 (1.04-2.70), P = 0.035; 3 months versus UC 0.69 (0.41-1.17), P = 0.174. Bayes factors indicated that for 12-month versus 3-month incentives and 12 months versus UC there was good evidence for the alternative hypothesis, and for 3 months versus UC there was good evidence for the null hypothesis.

CONCLUSIONS

This randomized controlled trial provides weak evidence that up to £300 of voucher incentives over 12 months is effective for maintaining smoking abstinence postpartum compared with usual care. There was good evidence that 12-month incentives are superior to those over only 3 months, for which there was no evidence of effectiveness relative to usual care.

How and why do financial incentives contribute to helping people stop smoking? A realist review

BACKGROUND

Tobacco smoking remains a key cause of preventable illness and death globally. In response, many countries provide extensive services to help people to stop smoking by offering a variety of effective behavioural and pharmacological therapies. However, many people who wish to stop smoking do not have access to or use stop smoking supports, and new modes of support, including the use of financial incentives, are needed to address this issue. A realist review of published international literature was undertaken to understand how, why, for whom, and in which circumstances financial incentives contribute to success in stopping smoking for general population groups and among pregnant women.

METHODS

Systematic searches were undertaken from inception to February 2022 of five academic databases: MEDLINE (ovid), Embase.com, CIHAHL, Scopus and PsycINFO. Study selection was inclusive of all study designs. Twenty-two studies were included. Using Pawson and Tilley's iterative realist review approach, data collected were screened, selected, coded, analysed, and synthesised into a set of explanatory theoretical findings.

RESULTS

Data were synthesised into six Context-Mechanism-Outcome Configurations and one overarching programme theory after iterative rounds of analysis, team discussion, and expert panel feedback. Our programme theory shows that financial incentives are particularly useful to help people stop smoking if they have a financial need, are pregnant or recently post-partum, have a high threshold for behaviour change, and/or respond well to external rewards. The incentives work through a number of mechanisms including the role their direct monetary value can play in a person's life and through a process of reinforcement where they can help build confidence and self-esteem.

CONCLUSION

This is the first realist review to synthesise how, why, and for whom financial incentives work among those attempting to stop smoking, adding to the existing evidence demonstrating their efficacy. The findings will support the implementation of current knowledge into effective programmes which can enhance the impact of stop smoking care.

PROSPERO REGISTRATION NUMBER

CRD42022298941.

Understanding for whom, under what conditions and how smoking cessation services for pregnant women in the United Kingdom work-a rapid realist review

BACKGROUND

Maternal smoking in pregnancy is associated with several adverse maternal and infant health outcomes including increased risk of miscarriage, stillbirth, low birth weight, preterm birth, and asthma. Progress to reduce rates of smoking at time of delivery in England have been slow and over the last decade, less than half of pregnant women who accessed services went onto report having quit. This realist review was undertaken to improve the understanding of how smoking cessation services in pregnancy work and to understand the heterogeneity of outcomes observed.

METHODS

The initial programme theory was developed using the National Centre for Smoking Cession and Training Standard Treatment Programme for Pregnant Women and the National Institute for Health and Care Excellence guidance on treating tobacco dependency. A search strategy and inclusion criteria were developed. Four databases were searched to identify published papers and four websites were hand searched to identify any unpublished literature that could contribute to theory building. Realist logic was applied to the analysis of papers to identify the contexts in which the intended behaviour change mechanism(s) were triggered, or not, and towards what outcomes to develop context mechanism outcome configurations.

RESULTS

The review included 33 papers. The analysis produced 19 context mechanism outcome configurations structured under five closely interconnected domains (i) articulating harm, (ii) promoting support, (iii) managing cravings, (iv) maintaining commitment and (v) building self-efficacy. This review identifies two key processes involved in how services achieve their effects: how material resources are implemented and relationships. Of the two key processes identified, more existing literature was available evidencing how material resources are implemented. However, the review provides some evidence that non-judgemental and supportive relationships with healthcare workers where regular contact is provided can play an important role in interrupting the social cues and social practice of smoking, even where those around women continue to smoke.

CONCLUSIONS

This review clarifies the range of interconnected and bi-directional relationships between services and the personal and social factors in women's lives. It underscores the importance of aligning efforts across the models five domains to strengthen services' ability to achieve smoking cessation.

Inequalities in smoking among pregnant women in North West London

BACKGROUND

London has the lowest smoking prevalence among pregnant women in England. However, it was unclear whether the low overall prevalence masked inequalities. This study investigated the prevalence of smoking among pregnant women in North West London stratified by ethnicity and deprivation.

METHODS

Data regarding smoking status, ethnicity and deprivation were extracted from electronic health records collected by maternity services at Imperial Healthcare NHS Trust between January 2020 and August 2022.

RESULTS

A total of 25 231 women were included in this study. At the time of booking of antenatal care (mean of 12 weeks), 4% of women were current smokers, 17% were ex-smokers and 78% never smokers. There were marked differences in the smoking prevalence between ethnic groups. Women of Mixed-White and Black Caribbean ethnicity and White Irish women had the highest prevalence of smoking (12 and 9%, respectively). There was an over 4-fold increase in the prevalence of smoking between the most and the least deprived groups (5.6 versus 1.3%).

CONCLUSIONS

Even in a population with an overall low prevalence of smoking in pregnancy, women experiencing deprivation and from certain ethnic backgrounds have a high smoking prevalence and hence are the most likely to benefit from smoking cessation interventions.

Smoking cessation in pregnant women using financial incentives: a feasibility study

BACKGROUND

The high prevalence of smoking pregnant women in Dutch areas with lower socioeconomic status and the consecutively harmful exposure to tobacco to both mother and child, depicted a high need for a novel intervention. According to other studies, the utilisation of financial incentives appeared to be a promising method for smoking cessation in pregnant women. Therefore, the aim of this study was to investigate the feasibility of implementing contingent financial incentives as smoking cessation support for pregnant women in the Netherlands.

METHODS

Feasibility study consisting of four developmental phases: (1) acceptability of Dutch population regarding financial-incentive-intervention by conducting an online questionnaire, (2) composing a pilot study utilising the financial-incentive-intervention in clinical practice, (3) execution of the composed pilot study and (4) evaluation of the executed pilot study utilising a mixed-methods approach. A financial-incentive-intervention, given in a contingent financial scheme (during five consequential appointments, respectively €25/€50/€100/€150/€250), if smoking abstinence was proven by the amount of cotinine in the urine of the pregnant women measured utilising a urine dipstick test. The public acceptability for the financial-incentive-intervention was assessed using 5-Likert scales. The number of pregnant women able to abstain from smoking during the pilot study and utilising the financial-incentive-intervention in clinical practice were used to assess the prosperity and practicality of the pilot study respectively. The pilot study was evaluated using a mixed-methods approach.

RESULTS

In total, 55.1% of the Dutch population sample (n = 328) found a financial incentive inappropriate for smoking cessation in pregnant women, while the healthcare professionals and pilot study participants thought the financial-incentive-intervention to be a helpful approach. Eleven vouchers were given during the pilot study, and one woman completed all test points and tested negative for cotinine at the end of the pilot study.

CONCLUSION

Although the financial-incentive-intervention appeared to be a promising approach for smoking cessation in pregnant women, the acceptability of the Dutch population and the number of pregnant women able to abstain smoking during this pilot study was low. Despite the limited study population, this study proved the concept of this financial-incentive-intervention to be feasible for implementation in the Netherlands.

TRIAL REGISTRATION

Not applicable since this is a feasibility study prior to a trial.

Usual care in a multicentre randomised controlled trial of financial incentives for smoking cessation in pregnancy: qualitative findings from a mixed-methods process evaluation

OBJECTIVES

Financial incentives are recommended by the UK's National Institute for Health and Care Excellence to aid smoking cessation in pregnancy. However, little is known about how implementation contexts might impact on their effectiveness. Variations in smoking cessation support (usual care) for pregnant women who smoke were examined qualitatively as part of a prospective process evaluation of the Cessation in Pregnancy Incentives Trial (CPIT III).

DESIGN

Longitudinal case studies of five CPIT III trial sites informed by realist evaluation.

SETTING

A stop smoking service (SSS) serving a maternity hospital constituted each case study, located in three UK countries.

PARTICIPANTS

Data collection included semistructured interviews with trial participants (n=22), maternity (n=12) and SSS staff (n=17); and site observations and perspectives recorded in fieldnotes (n=85).

RESULTS

Cessation support (usual care) for pregnant women varied in amount, location, staff capacity, flexibility and content across sites. SSS staff capacity was important to avoid gaps in support. Colocation and good working relationships between maternity and SSS professionals enabled prioritisation and reinforced the importance of smoking cessation. Sites with limited use of carbon monoxide (CO) monitoring reduced opportunities to identify smokers while inconsistency around automatic referral processes prevented the offer of cessation support. SSS professionals colocated within antenatal clinics were available to women they could not otherwise reach. Flexibility around location, timing and tailoring of approaches for support, facilitated initial and sustained engagement and reduced the burden on women.

CONCLUSIONS

Trial sites faced varied barriers and facilitators to delivering cessation support, reflecting heterogeneity in usual care. If financial incentives are more effective with concurrent smoking cessation support, sites with fewer barriers and more facilitators regarding this support would be expected to have more promising trial outcomes. Future reporting of trial outcomes will assist in understanding incentives' generalisability across a wide range of usual care settings.

TRIAL REGISTRATION NUMBER

ISRCTN15236311.