Table 3.

Primary and secondary outcome measures

Outcome	Time point	Data collection	Variables/method
Primary outcomes—pilot study
Feasibility	Study completion	Database + weekly interview	Recruitment rate (number recruited/number screened) Retention rates (number completing last follow-up/number recruited) CO sample rate (actual COs completed/total possible COs) Number of counselling sessions completed Number of women taking NRT Adherence to NRT (proportion of dispensed NRT consumed)113 Partners/household members receiving NRT
Acceptability	Study completion	In-depth interviews and focus groups	Qualitative interviews with participants and antenatal staff will explore: Acceptability of the intervention Perceived effectiveness of intervention components Attitudes toward addressing tobacco smoking Barriers and facilitators to the implementation of the intervention as routine antenatal care
	Monthly	Interview	Treatment Acceptability Questionnaire
Secondary outcomes—intervention effectiveness
Changes in tobacco smoking	At birth	Weekly interview	Number of abstinent days (≤5 ppm; actual number of days/total possible number of days) Self-reported 7-day point prevalence verified by CO at birth ≤5ppm Self-reported reduction in number of cigarettes smoked/day in past 7 days at 12 weeks postpartum Changes in management of smoke-free home/cars
Adverse maternal outcomes	During pregnancy and to 12 weeks postpartum	Medical chart review	Participant adverse maternal outcomes will be compared with those of historical controls. The outcomes will incorporate: Rates of miscarriage Ectopic pregnancy Preterm labour and birth Stillbirth Intrauterine growth restriction Placenta praevia Placental abruption and premature rupture of the membranes
Neonatal outcomes	At birth and at 12 weeks postpartum	Medical chart review	Participant newborn characteristics will be compared with historical controls, including: Birth weight Head circumference Gender Gestational age at delivery Malformations (including cleft lip/palate, gastroschisis, heart defects) Sudden infant death syndrome
Economic evaluation	Study completion	Cost-consequence analysis	Costs incurred: Financial incentives NRT and delivery CO monitoring equipment Counselling wages and other associated costs Administration wages and other associated costs Patient costs (out-of-pocket expenses) Overheads Offsets: Reductions in costs of smoking Outcomes: Abstinence at delivery Reductions in CO at delivery

CO, carbon monoxide; NRT, nicotine replacement therapy; ppm, parts per million.