Supporting expectant mothers to quit smoking

Study participants will be allocated to one of two groups (Control Group [CG] or Treatment Group [TG]) during the baseline/enrolment visit. In the Control group/condition, only the participant (pregnant smoker) will be eligible to receive the voucher incentives. In the Treatment group/condition, the participant will be asked to nominate a quit partner (where appropriate their spouse) who will also be eligible to receive incentive vouchers if the participant verifies as quit during monthly follow-up. Control group participants will be advised that they will be eligible to receive a monthly incentive ($50 voucher) if, during follow up study visits and telephone calls, they self-report and verify (via exhaled breath carbon monoxide [CO] measurement of between 0-6ppm) as quit. Participants will be required to attend three study visits (Baseline/Enrolment [V1], end of pregnancy [V2], and two months postpartum [V3]) where they will complete questionnaires relating to their smoking history, intention to quit, smoking knowledge, reasons for quitting, and perceived partner support. Additionally, researchers will contact participants monthly during the study, via telephone, to determine their smoking status. If during these monthly telephone calls the participant reports being quit, they will be invited back to the study centre to verify their quit status, and receive the quit contingent incentive. Study duration will be approximately 12 months, from time of enrolment antepartum to 6 months postpartum. A final 12 month postpartum follow up telephone call will also be conducted to determine the long-term effects of the intervention. All participants will be eligible to receive up to $570 if they verify as abstinent for the duration of the study. The $570 comprises up to 11 x $50 vouchers if they have quit, and 2 x $10 vouchers for visits V1 and V3. In the Treatment condition, the participant and their support partner will be eligible to receive up to $570 and $550 respectively, if the pregnant participant verifies as quit during monthly study visits for the duration of the study. Note: the total incentive voucher sum is less for the partner given they do not attend the V1 and V3 visits, and therefore do not receive the $10 vouchers allocated to these visits. All study participants will additionally be provided with quit materials and a ‘Partner Pack’, which will provide their ‘quit buddy’ with useful resources. The participant quit materials comprise publicly available pregnancy-specific written materials (developed by the Australian Government Dept of Health and Cancer Council Australia) and provided by Quit Tasmania (for example, "Quit for you, Quit for two", "Smoking and pregnancy factsheet", "Health risks of smoking during pregnancy", "Sudden Infant Death Syndrome: SIDS and Kids information sheet on smoking", "Quit Book" and Quitline information), as well as a list of other publicly available government-funded resources (smartphone apps, websites) and health professionals (GP, smoking cessation clinical nurse consultant) who can assist in the quit process. The 'Partner Pack' comprises publicly available written materials (provided by Cancer Council and Quitline) largely directed at the male partners (irrespective of smoking status) of expectant women who smoke, and provides information on how best to support the expectant woman in her quit attempt (e.g. "The effect of second-hand smoke on children", "12 tips to support your quitter", "Helping a smoker quit: Do's and don'ts", "Important news for fathers who smoke", "Products to help you quit smoking", and "Quit for good factsheet").