A new trial from France published in The BMJ has shown that pregnant women are more likely to stop smoking if financial incentives are offered as part of a treatment plan.
Stopping smoking is vital for the mother and baby, yet evidence suggests that less than half of women who are daily smokers successfully quit during pregnancy. Pregnant women who smoke can harm themselves and their unborn baby in ways such as, premature births, damaging babies developing lungs, and causing birth defects.
Previous studies of financial incentives have shown promising results but have not yet been put into practice.
Using incentives for smoking pregnant women
The researchers aimed to assess the effectiveness of progressively higher financial incentives dependant on continuous smoking abstinence on stopping smoking and birth outcomes amongst pregnant smokers.
The trial involved 460 pregnant women who smoked (average age 29 years) at 18 maternity wards in France who were randomly assigned either a financial incentives group (231) or a control group (229) when they were less than 18 weeks into their pregnancy.
The participants completed six 10-minute face-to-face visits and were asked to set a quit date. They were also given motivational counselling and support to prevent the possibility of relapse. Individuals in the control group received a €20 (£17) voucher at the end of each visit, however, abstinence was not rewarded, therefore they could only receive a maximum of €120 after six visits. Whereas participants in the financial incentive group had the potential to earn additional vouchers dependant on abstinence (confirmed by measuring by the amount of carbon monoxide on the participant’s breath at each visit). This meant that the pregnant women who were abstinent during six consecutive visits could earn up to €520 in vouchers.
Other potential factors were considered such as:
- Age.
- Ethnicity.
- Income.
- Use of nicotine replacement therapy was taken into account and other (secondary) measures were recorded at each visit, including time to relapse, nicotine withdrawal symptoms, blood pressure, and alcohol and cannabis use in the past 30 days.
The findings revealed that pregnant women in the financial incentives group smoked 163 fewer cigarettes than those in the control group.
The continuous abstinence rate was significantly higher in the financial incentives group (16%, 38 out of 231) than in the control group (7%, 17 out of 229) and, visit by visit, the abstinence rate was 4 times more likely in the intervention than in the control group.
Time to relapse occurred significantly later and craving for tobacco was lower in the financial incentives group than in the control group. No difference was detected for nicotine withdrawal symptoms, blood pressure, or cannabis or alcohol use.
Analysing the outcome of the babies
Further analyses suggested that babies in the financial incentives group were around twice as likely to have birth weights of 2500 g or more than in the control group, although the researchers say these results should be interpreted with caution.
Secondary measures in newborns were also recorded, including gestational age at birth (in weeks), birth weight, head circumference, Apgar score at five minutes, and poor outcome (a combined measure of transfer to the neonatal unit, birth defects, convulsions, or perinatal death).
Financial incentives were also 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.
However, researchers accepted that there were some limitations to the trial including the lack of mother and baby follow-up after delivery and the lack of involvement of partners in the intervention who smoked. However, they said the results suggest that financial incentives progressively rewarding smoking abstinence “could be implemented in the routine healthcare of pregnant smokers.”
Future studies “should assess the long-term effectiveness of financial incentives on smoking abstinence after delivery,” the researchers concluded.
This 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, say researchers in a linked editorial. They argue that implementation should be pursued in parallel with ongoing and future research and point to the need for integration of incentives in national best practice guidelines alongside appropriate ethical and cultural considerations.
