Increasing cash incentives improved quit rates, newborn birth weights

Pregnant smokers who were given cash vouchers to reward abstinence were more likely to stop smoking compared to women who were not rewarded for abstinence, according to results from the French Financial Incentive for Smoking Cessation in Pregnancy (FISCP) trial.

Given the limited or low certainty evidence for pharmacotherapy interventions and nicotine replacement therapy to increase smoking abstinence in pregnant women, the idea of using financial incentives to prompt quitting has gained traction in recent years. Previous trials, as well as a 2019 Cochrane review, have suggested that financial incentives may be a promising intervention among pregnant women, but this approach has not been widely implemented in clinical practice, Ivan Berlin, MD, PhD, of Département de pharmacologie, Hôpital Pitié-Salpêtrière-Sorbonne Université in Paris, and colleagues from the FISCP trial explained in The BMJ.

For their analysis, Berlin and colleagues assessed the efficacy of progressively higher financial incentives on continuous smoking abstinence among pregnant smokers, with the financial reward increasing depending on length of smoking cessation. The study authors also assessed the strategy’s impact on point prevalence smoking abstinence, tobacco cravings, withdrawal symptoms, weight, blood pressure, and birth outcomes.

“In this multicenter randomized controlled trial, financial incentives rewarding smoking abstinence compared with no financial incentives were associated with significantly increased continuous and point prevalence abstinence rates, a prolongation in the time to relapse, and a reduction in craving for tobacco,” the FISCP investigators found. “Financial incentives were also associated with a decrease in the probability of having a low birthweight baby.”

Berlin and colleagues concluded that financial incentives that progressively reward smoking abstinence “could be implemented in the routine health care of pregnant smokers. Future studies should assess the long-term effectiveness of financial incentives on smoking abstinence after delivery.”

The FISCP was conducted among 460 pregnant smokers (18 years or older; smoked ≤5 cigarettes a day or ≥3 roll-your-own cigarettes a day; gestation <18 weeks) in 18 maternity wards in France. All participants were motivated to quit smoking and affiliated with the social health insurance system.

Participants were randomized to either a financial incentives group or a control group. The 231 women in the incentives group received a €20 voucher at the end of each of six monthly study visits as a show-up fee, plus additional vouchers depending on their smoking abstinence. Thus, they received a reward for their abstinence as of the current visit, as well as a reward for past abstinence, with the pay-off increasing with each visit. For example, participants who received incentives got €20 at their first study visit (randomization), €20+€40 at the second visit, €20+€60 at their third visit, and so on, to a maximum pay-off of €520.

The 229 women randomized to the control group received only the €20 show-up fee at the end of each visit, for a maximum of €120.

At each visit, all participants in both groups received a minimum 10-minute intervention for smoking cessation according to international guidelines, including motivational counselling, support, relapse prevention, and skills training.

The primary outcome measure was continuous smoking abstinence from the first post-quit date visit to visit six, prior to delivery—abstinence was defined as a self-report of no smoking in the past seven days and expiratory carbon monoxide (eCO) less than or equal to 8 ppm measured by a Bedfont Smokelyzer piCO. Secondary outcomes included point prevalence abstinence, time to smoking relapse, withdrawal symptoms, blood pressure, and alcohol and cannabis use in the past 30 days.

The study authors also recorded secondary outcomes in newborns, including gestational age at birth, birth characteristics (weight, length, head circumference, Apgar score), and a poor neonatal outcome, comprised of a composite measure of transfer to the neonatal unit, congenital malformation, convulsions, or perinatal death.

Mean participant age was 29 years, and overall median cigarettes smoked in the past seven days was 60.

“The continuous abstinence rate was significantly higher in the financial incentives group (16%, 38/231) than control group (7%, 17/229): odds ratio 2.45 (95% confidence interval 1.34 to 4.49), P=0.004,” the study authors reported. “The point prevalence abstinence rate was higher (4.61, 1.41 to 15.01, P=0.011), the median time to relapse was longer (visit 5 [interquartile range 3-6] and visit 4 [3-6], P<0.001), and craving for tobacco was lower (β=−1.81, 95% confidence interval −3.55 to −0.08, P=0.04) in the financial incentives group than control group. Financial incentives were associated with a 7% reduction in the risk of a poor neonatal outcome: 4 babies (2%) in the financial incentives group and 18 babies (9%) in the control group: mean difference 14 (95% confidence interval 5 to 23), P=0.003.”

Notably, post hoc analyses seem to suggest that babies born of mothers in the incentive group seemed to have a higher birth weight, Berlin and colleagues added.

“Post hoc analyses suggested that more babies in the financial incentives group had birth weights ≥2500 g than in the control group: unadjusted odds ratio 1.95 (95% confidence interval 0.99 to 3.85), P=0.055; sex adjusted odds ratio 2.05 (1.03 to 4.10), P=0.041; and sex and prematurity adjusted odds ratio 2.06 (0.90 to 4.71), P=0.086,” they wrote. However, as these findings were part of a post hoc analysis, the results should be interpreted with caution, they noted.

These findings, as well as the 2019 Cochrane review and other recent analyses, “provide compelling evidence that incentives effectively promote smoking cessation during pregnancy,” Leonieke J. Breunis, MD, of the University Medical Centre Rotterdam in the Netherlands, and colleagues wrote in an accompanying editorial. “Although the effect of incentives on birth outcomes is less clear overall, epidemiological evidence clearly indicates that smoking cessation during pregnancy is associated with a reduction in most adverse perinatal health risks. As such, it is reasonable to assume that cessation will translate into perinatal and child health benefits at the population level. Given the clear signal that financial incentives support pregnant smokers to quit, how should this be taken forward?”

Breunis and colleagues suggested that ongoing and future studies will be necessary to answer the remaining questions, including the optimal incentive “scheme,” including timing, frequency, value, duration, and incentive type; who should deliver that incentive strategy, and how; whether personalized incentives are more effective than a one-size-fits-all approach; whether involvement of a significant other in the intervention would increase efficacy; and whether extending the intervention to the postpartum period could sustain smoking cessation.

The editorial authors also argued that clinicians should not sit idly by while studies are being conducted to further hone such incentive-based approaches; rather, they suggested that financial incentives for smoking cessation be implemented “in parallel with ongoing and future studies.”

“Berlin and colleagues’ study adds to growing evidence that the time is right to start including incentives as part of standard practice to support smoking cessation during pregnancy,” they wrote. “Doing so will also play an important role in reducing health inequalities at their earliest origin.”

Study limitations included a lack of follow-up post-delivery; a possible inability to generalize results to other countries and cultures; not including smokers who used e-cigarettes specifically; a lack of real-world cost efficacy data on financial incentives to encourage smoking cessation; and the inability to include urinary anabasine and anatabine as an objective control of tobacco intake due to low sensitivity and specificity.

  1. Pregnant smokers who were given cash vouchers to reward smoking abstinence were more likely to abstain compared to women who were not rewarded, according to results from the French Financial Incentive for Smoking Cessation in Pregnancy (FISCP) trial.

  2. Financial incentives were also associated with a decrease in the probability of having a low birthweight baby; however, as this finding stemmed from post hoc analyses, it should be interpreted with caution.

John McKenna, Associate Editor, BreakingMED™

The study was funded by the French National Cancer Institute (INCa) Recherche en Prévention Primaire (grant No 2014100).

Coauthor Goldzahl received support from the INCa grant. No other relevant relationships were disclosed.

The editorial authors had no relevant relationships to disclose.

Cat ID: 41

Topic ID: 83,41,730,41,143,489,925