Quitting Using Incentives Trial for a HEaLthy Pregnancy (QUIT-HELP)

Women randomised to the Intervention group will be offered financial incentives in the form of voucher gift cards, for smoking abstinence as measured by CO breath analysis. The vouchers increase in value during pregnancy from $50, to $150 and then $400. CO breath analyses will be conducted at routine antenatal appointments using the piCObaby smokerlyzer . Women nominate a ‘quit date’ within 2 weeks of providing informed consent. At 2 weeks following the quit date, women will be provided with $50 if they provide a negative CO breath analysis at their next routine antenatal appointment. Women will be given $150 if they provide a negative CO breath analysis at approximately 12 weeks after their quit date. At their 37-week appointment, women will provide breath and urine samples and will be given a $400 voucher upon confirmation of abstinence via CO breath analysis. The breath analysis only needs to be negative for tobacco use to receive the incentive. A CO breath analysis of >=4 ppm is considered abstinent. Abstinence will be rewarded at any stage but if participants had not quit at a previous appointment the reward will revert to the lower amount. For example, if a woman was not abstinent at 16 weeks ($0 reward) but was abstinent at 26 weeks and 37 weeks they would receive $50 and then $150, respectively. The maximum value of the financial incentive is $600. Urinary analysis will be conducted in batch testing at completion of the trial to provide further insights into tobacco use and abstinence behaviours. However, urinary analysis results will not be used to determine financial incentives.