Financial Incentives for Preventing Postpartum return to Smoking (FIPPS): study protocol for a three-arm 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.

Contingency management interventions for abstinence from cigarette smoking in pregnancy and postpartum: A systematic review and meta-analysis

Contingency management is one of the most effective treatments for substance use disorders in not-pregnant people. The most recent quantitative review of its efficacy among pregnant and postpartum women who smoke cigarettes concluded with moderate certainty that those receiving contingent financial incentives were twice as likely to be abstinent compared with controls. We aimed to update and extend previous reviews. Five databases were systematically searched for randomized controlled trials (RCTs) published before December 2022 that assessed the effectiveness of incentives for abstinence from substance use. Data from trials of smoking abstinence were pooled using a random-effects meta-analysis model (restricted maximum likelihood). Results are reported as risk-ratios (RRs) with 95% confidence intervals (CIs). This study is registered with PROSPERO, CRD42022372291. Twelve RCTs (3136) pregnant women) were included. There was high certainty evidence that women receiving incentives were more likely to be abstinent than controls at the last antepartum assessment (12 RCTs; RR = 2.43, 95% CI 2.04-2.91, n = 2941, I2 = 0.0%) and moderate certainty evidence at the longest postpartum assessment while incentives were still available (five RCTs; RR = 2.72, 1.47-5.02, n = 659, I2 = 44.5%), and at the longest postpartum follow-up after incentives were discontinued (six RCTs; RR = 1.93, 1.08-3.46, n = 1753, I2 = 51.8%). Pregnant women receiving incentives are twice as likely to achieve smoking abstinence during pregnancy suggesting this intervention should be standard care for pregnant women who smoke. The results also demonstrate that abstinence continues into the postpartum period, including after incentives are discontinued, but more trials measuring outcomes in the postpartum period are needed to strengthen this conclusion.

Insights into Prevention of Health Complications in Small for Gestational Age (SGA) Births in Relation to Maternal Characteristics: A Narrative Review

Small for gestational age (SGA) births are a significant clinical and public health issue. The objective of this review was to summarize maternal biological and socio-demographic factors and preventive strategies used to reduce the risk of SGA births. A literature search encompassing data from the last 15 years was conducted using electronic databases MEDLINE/PubMed, Google Scholar and Scopus to review risk factors and preventive strategies for SGA. Current evidence shows that primiparity, previous stillbirths, maternal age ≤24 and ≥35 years, single motherhood, low socio-economic status, smoking and cannabis use during pregnancy confer a significant risk of SGA births. Studies on alcohol consumption during pregnancy and SGA birth weight are inconclusive. Beneficial and preventive factors include the "Mediterranean diet" and dietary intake of vegetables. Periconceptional folic acid supplementation, maternal 25-hydroxyvitamin D, zinc and iron levels are partly associated with birth weight. No significant associations between COVID-19 vaccinations and birthweight are reported. A midwifery-led model based on early and extensive prenatal care reduces the risk of SGA births in women with low socio-economic status. Major preventive measures relate to the awareness of modifiable and non-modifiable risk factors of SGA, leading to changes in parents' lifestyles. These data support that education, monitoring during pregnancy, and implementing preventive strategies are as important as biological determinants in risk reduction of SGA births.

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

OBJECTIVE

To examine effectiveness, cost effectiveness, generalisability, and acceptability of financial incentives for smoking cessation during pregnancy in addition to variously organised UK stop smoking services.

DESIGN

Pragmatic, multicentre, single blinded, phase 3, randomised controlled trial (Cessation in Pregnancy Incentives Trial phase 3 (CPIT III)).

SETTING

Seven UK stop smoking services provided in primary and secondary care facilities in Scotland, Northern Ireland, and England.

PARTICIPANTS

944 pregnant women (age ≥16 years) who self-reported as being smokers (at least one cigarette in the past week) when asked at first maternity visit, less than 24 weeks' gestation, and notified to the trial team by routine stop smoking services.

INTERVENTIONS

Participants in the control group were offered the standard stop smoking services, which includes the offer of counselling by specially trained workers using withdrawal orientated therapy and the offer of free nicotine replacement therapy. The intervention was the offer of usual support from the stop smoking services and the addition of up to £400 ($440; €455) of LoveToShop financial voucher incentives for engaging with current stop smoking services or to stop smoking, or both, during pregnancy.

MAIN OUTCOME MEASURES

Self-reported smoking cessation in late pregnancy (between 34 and 38 weeks' gestation) corroborated by saliva cotinine (and anabasine if using nicotine replacement products). Results were adjusted for age, smoking years, index of multiple deprivation, Fagerström score, before or after covid, and recruitment site. Secondary outcomes included point and continuous abstinence six months after expected date of delivery, engagement with stop smoking services, biochemically validated abstinence from smoking at four weeks after stop smoking date, birth weight of baby, cost effectiveness, generalisability documenting formats of stop smoking services, and acceptability to pregnant women and their carers.

RESULTS

From 9 January 2018 to 4 April 2020, of 4032 women screened by stop smoking services, 944 people were randomly assigned to the intervention group (n=471) or the control group (n=470). Three people asked for their data to be removed. 126 (27%) of 471 participants stopped smoking from the intervention group and 58 (12%) of 470 from the control group (adjusted odds ratio 2.78 (1.94 to 3.97) P<0.001). Serious adverse events were miscarriages and other expected pregnancy events requiring hospital admission; all serious adverse events were unrelated to the intervention. Most people who stopped smoking from both groups relapsed after their baby was born.

CONCLUSIONS

The offer of up to £400 of financial voucher incentives to stop smoking during pregnancy as an addition to current UK stop smoking services is highly effective. This bolt-on intervention supports new guidance from the UK National Institute for Health and Care Excellence, which includes the addition of financial incentives to support pregnant women to stop smoking. Continuing incentives to 12 months after birth is being examined to prevent relapse.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN15236311.