Financial incentives, such as shopping vouchers, could help one in five women quit smoking during pregnancy, according to a new UK research.
The study, led by researchers at the University of Cambridge and King's College London, found that only a small number of women 'gamed' the system to receive the incentives while continuing to smoke.
Researchers carried out a study of women attending antenatal clinics at a hospital in Chesterfield, Derbyshire, an area of high deprivation and 239 pregnant women enrolled into the financial incentives scheme.
At each visit to the antenatal clinic, the women were asked if they had smoked since the last visit and were given a carbon monoxide breath test (which showed positive if the individual had smoked in the preceding few hours).
If they had not smoked, they were given a shopping voucher - the first voucher was worth 8 pounds and the value increased by 1 pound for each visit up, providing a potential maximum of 752 pounds in vouchers.
Testing positive for smoking resulted in the incentive being withheld at that visit and the value being reset to 8 pounds for the next visit; following two consecutive test results indicating no smoking, the incentive was re-set to the highest point attained prior to the lapse.
The researchers also used saliva samples from the women to assess at time of delivery and then six months later whether the women had stopped smoking, complemented with urinary and saliva tests at enrolment, 28 and 36 weeks into pregnancy and then two days and six months after the birth of their child.
Of the women who enrolled into the scheme, 143 received at least one voucher, suggesting that they had attempted to quit. One in five of the women (48 women) had managed to quit by the time of delivery.
The study found that 25 women (4 per cent of the entire cohort) were still not smoking six months after the birth of their child.
This compared to the previous year, when only a very small number of women (less than 1 per cent) were recorded as having stopped smoking.
In all cases, women from areas of highest deprivation were the least likely to succeed in quitting. Urinary or salivary tests suggested that ten women (4 per cent) had smoked cigarettes whilst claiming vouchers.
In total, 37,490 pounds was spent on the financial incentive, which the researchers believe is likely to prove an acceptable ratio of cost to benefit.
Based on modelling of other interventions for smoking cessation in pregnancy, they argue it is most likely that these schemes would fall within the acceptable range of cost effectiveness set by the National Institute for Health and Care Excellence (NICE) in the UK.
The study is published in the journal Addiction.
