Table 2.

Data Input Categories and Sources

Activity	Data Source and Explanation
	Costs of Clinical Tasks
Prepare for visit	Clinic staff estimated average time spent preparing for each visit. Time estimate multiplied by labor cost per hour (see text and supplement).
Brief counseling	Time recorded on DATCAP and valued using labor cost per hour (see text)
Deliver smoking- contingent voucher incentive	Time recorded on DATCAP and valued using labor cost per hour (see text)
Purchase client vouchers	Time recorded on DATCAP and valued using labor cost per hour (see text)
Drive to/from off-site visits	Time recorded on DATCAP and valued using labor cost per hour (see text)
Follow-up after missed appointments	Clinic staff estimated average time spent per week. Converted to average time per visit using client visits per week in each group. Time spent multiplied by labor cost per hour (see text and supplement).
Urine processing, review results, disposal	Clinic staff estimated average time spent per visit. Time spent multiplied by labor cost per hour (see text).
Purcard verification	Staff members verified voucher purchases made for clients on University Purcards: credit cards used in this study to purchase retailer credits for clients awarded financial incentives. Clinic staff estimated average time spent per week on the verifications. Results were converted to average time per visit using visits per week. Time per visit was multiplied by labor cost per hour (see text).
Record mileage	Clinic staff estimated average time spent per week. Results were converted to average time per visit using visits per week. Time spent was multiplied by labor cost per hour (see text).
Complete required training	Clinic staff estimated annual training time. Converted to average time spent per visit using total study months and total visits over the timespan of the study.
	Costs of Other Inputs
Voucher Spending Amounts	Recorded on Purcard invoices and abstracted to study database
Supplies
Office supplies	Study receipts
Urinalysis supplies	Study receipts Lease cost/sq. ft. for clinical office space multiplied by workspace area (299
Clinic Workspace	sq. ft.) multiplied by fraction of time used for study and then apportioned to participants based on time spent in visits
Office Cubicle (desk, chair, divider walls)	Total purchase cost of $750 was amortized over 20 years at a 3% rate per year and apportioned to the study timeframe based on the duration of the study and then divided by number of participants
Clinic Staff Vehicle Use	$0.57 per mile times number of miles (University rate)
	Client Transportation & Time Costs
Transportation	Total transportation cost for bus/taxi and care recorded on DATCAP (see text)
Travel time	Time recorded on DATCAP and valued using a travel cost per hour (Verbooy et al., 2018).
	Intervention Benefits
Medicaid Cost Offsets	Reduction in rate of infants small for gestational age (SGA) times difference in Medicaid payments for delivery, newborn, and first year of life for infant SGA versus not SGA
ADP (Absolute Difference in Percent)	Excel calculation based on abstinence in control and adjusted odds ratio for abstinence (intervention versus control) at 24 weeks postpartum
Mother’s QALY Gain	Using Stapleton & West (2012), Table 2 for 48 weeks since quit date, interpolate entry corresponding to 3% discount rate and ADP.
Infant’s QALY Gain	Multiply lives saved based on improvement in abstinence at end of pregnancy times infant’s discounted life expectancy at birth.
Economic Benefits	Mother’s plus infant’s QALY gains times value per QALY ($100,000)