Paying pregnant women to quit smoking pays off, study says

Researchers have identified a common substance that makes smokers much more likely to kick the habit - money.

The promise of up to $600 in shopping vouchers proved a powerful inducement to get pregnant women to quit smoking. Compared with women who were merely referred for routine smoking-cessation services, those offered financial incentives were more than twice as likely to give up cigarettes, according to a new study from Scotland published in the journal BMJ.

Smoking is a major financial drain on Britain's National Health Service, according to the researchers who organized this unconventional clinical trial. About 1 in 4 pregnant women in Scotland smokes, which increases the risk of miscarriage, stillbirth, and infant death. Throughout Britain, the annual cost of treating pregnant smokers is somewhere between $12 million and $97 million, plus $18 million to $36 million to treat their babies.

So a group of researchers from Scotland and England screened pregnant women who were treated by the National Health Service in Greater Glasgow and Clyde. Women who said they had smoked at least one cigarette in the previous week had their breath tested for carbon monoxide; those who exhaled at least 7 parts per million of carbon monoxide were considered current smokers.

All of these women were referred to smoking-cessation specialists, who offer a face-to-face counseling session followed by four weekly phone calls and 10 weeks of free nicotine replacement therapy. About half of study participants were also offered shopping vouchers for meeting certain goals, such as showing up for their counseling session, passing a breath test if they went two weeks without smoking, and remaining smoke-free for 12 weeks.

Among the 306 women who were eligible for the shopping vouchers, 69 had stopped smoking and were still smoke-free when they were 34 to 38 weeks into their pregnancies. Only 26 of the 303 women in the control group had done the same. That meant the women offered financial incentives were 2.63 times more likely to be nonsmokers at the end of their pregnancies, the researchers calculated.

Those results were better than the quit rates in most clinical trials of either behavioral or pharmaceutical interventions designed to help pregnant women quit smoking, the researchers noted.

Some of the women who said they had quit smoking were later found to have nicotine byproducts in their blood, saliva or urine.

Still, researchers said, considering the failures of other programs, the idea of financial incentives should be tested in a larger trial.