Cigarette Smoking
Conditions
Keywords
smoking, pregnancy, cessation, incentives
Brief summary
Investigators will examine whether adding financial incentives to current best practices for smoking cessation during pregnancy (i.e., referral to pregnancy-specific counseling using a telephone quit line) increases cessation rates and improves infant health. While more expensive upfront compared to best practices alone, the investigators hypothesize that this treatment approach will be economically justified by the later cost savings associated with more women quitting, having healthier babies, and needing less healthcare. It should also help to reduce the greater risk for health problems often seen among those who less well off economically.
Detailed description
Smoking during pregnancy is the leading preventable cause of poor pregnancy outcomes in the U.S. Most pregnant smokers continue smoking through pregnancy producing serious immediate and longer-term adverse health consequences for the infant. Smoking during pregnancy is highly associated with economic disadvantage and a substantive contributor to health disparities. Efficacious interventions are available, but cessation rates are low (\<20%) and improvements in birth outcomes often modest or absent. Current treatments usually entail relatively brief, lower-cost interventions (e.g., pregnancy specific quit lines). There is broad consensus that more effective interventions are sorely needed. This team of investigators has developed a novel behavioral economic intervention in which women earn financial incentives contingent on smoking abstinence. In a metaanalysis of treatments for smoking during pregnancy, effect sizes achieved with financial incentives were several fold larger than those achieved with lower intensity approaches or medications. The intervention also appears to improve birth outcomes and increase breastfeeding duration. While highly promising, further research is needed in at least three areas. (1) The evidence on birth outcomes and breastfeeding is from studies that combined data across trials rather than a single prospective trial, (2) whether the intervention produces other postpartum improvements in health has not been investigated, and (3) the overall cost-effectiveness of this approach has not been examined. To examine these unanswered questions, the investigators are proposing a randomized, controlled clinical trial comparing the efficacy and cost effectiveness through one year postpartum of current best practices for smoking cessation during pregnancy vs. best practices plus financial incentives among 230 pregnant, Medicaid recipients. A third condition of 115 pregnant nonsmokers matched to the smokers on sociodemographic and health conditions will be included as well to compare the extent to which the treatments reduce the burden of smoking and to estimate how much more might be accomplished by further improvements in this incentives intervention without exceeding cost-effectiveness. The investigators hypothesize that best practices plus financial incentives will be more effective than usual care practices alone, that the incentives intervention will be cost effective, and that while adding the incentives reduces a greater proportion of the health and economic burden of smoking than best practices alone, more can be done while remaining cost effective. Overall, the proposed study has the potential to substantially advance knowledge on cost-effective smoking cessation for pregnant women. Importantly, because of the strong association between smoking during pregnancy and economic disadvantage, the proposed study also has the potential to contribute new knowledge relevant to reducing the serious challenges of health disparities.
Interventions
BEHAVIORALBest practices
BEHAVIORALfinancial incentives
financial incentives provided contingent on biochemically confirmed smoking abstinence
Sponsors
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Centers for Disease Control and Prevention
University of Vermont
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
for two intervention arms: * report being smokers at the time that they learned of the current pregnancy; * report smoking in the 7 days prior to the first prenatal care visit with biochemical verification; * \< 25 weeks gestation; * English speaking; * plan on remaining in the geographical area through 12months postpartum. Inclusion Criteria for never-smoker comparison condition: * report being nonsmokers at the time they learned of the current pregnancy; * report no smoking in the past 6 month; * Biochemical verification of non-smoker status; * report smoking \< 100 cigarettes in their lifetime;
Exclusion criteria
* \> 25 weeks gestation; * unavailable for routine assessments through 1 year postpartum; * opioid substitution therapy; * untreated/unstable serious mental illness
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 7-day Point Prevalence Abstinence Levels at Final Antepartum Assessment | collected once per women at approximately 28-weeks gestation in each of the two smoking arms | Abstinence was defined as woman reports that she has not smoked, not even a puff, in the past 7 days and self-report is biochemically verified via urine cotinine testing |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 7-day Point Prevalence Abstinence Postpartum | Repeated assessments completed at 2-, 4-, 8-, 12-, 24-, and 48-weeks postpartum | Compare two treatment arms on 7-day point-prevalence abstinence assessed at 2-, 4-, 8-, 12-, 24- and 48-weeks postpartum. Abstinence was defined as self-report of no smoking in past 7 days, not even a puff, with biochemical verification of self-report using urine cotinine testing |
| Breastfeeding in the Three Trial Arms | Repeated assessments completed at 2-, 4-, 8-, 12-, 24-, and 48-weeks postpartum | Compare the three trial arms on overall percentage of women continuing to breastfeed at repeated postpartum assessments |
| Breastfeeding While Abstinent From Smoking | Repeated assessments completed at 2-, 4-, 8-, 12-, 24-, and 48-weeks postpartum | We compared the three trial arms on the percent of women who reported breastfeeding and were biochemically confirmed to be abstinent from smoking at each postpartum assessment. |
| Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | Outcomes reported for 8 assessments (early pregnancy, late pregnancy, 2, 4, 8, 12, 24, 28 weeks postpartum. | The craving item is on a 0 (none) to 4 (severe) scale. We report mean (SEM) scores. |
| Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | Outcomes reported for 8 assessments (early pregnancy, late pregnancy, 2, 4, 8, 12, 24, 28 weeks postpartum. | Reporting mean total scores and SEM from the Minnesota Nicotine Withdrawal Scale (MNWS). Total score is an average of 7 items, with each item on a 0 (none) to 4 (severe) scale. |
| Infant Growth in First Year of Life | delivery, 24-week, and 50-week postpartum assessments | Infant growth (length & weight) expressed a Body Mass Index (BMI) percentile score was assessed at delivery, 24- and 48-week postpartum assessments. |
| Birth Outcomes (% Small for Gestational Age Deliveries) | delivery | Birth outcomes were compared between the three study arms. Small for gestational age was defined as \<10th percentile using INTERGROWTH-21st \[2021\] https://intergrowth21.tghn.org/about/about-us/. |
| Birth Outcomes (NICU Admissions) | at delivery | Compared three trial conditions on percent of NICU admissions |
| Ages & Stages Questionnaire (ASQ) | 24- and 48-weeks postpartum | The ASQ assesses infant development in five areas (communication \[Comm\], gross motor \[GM\], fine motor \[FM\], problem solving \[PrbSlv\], personal-social \[PerSoc\]); Each area includes six items, each with a possible value of 0, 5, 10, along with a cutoff to dichotomize infants into typical/normal vs. monitor/potential delay categories for an area. Scores in each area are compared to norms; scores with 1 standard deviation of the norm mean are categorized as typical/normal and those greater than one standard deviation below the norm mean are categorized as monitor/potential delay. We report the dichotomized outcomes for each of the six areas at the 24-week and 48-week assessments noting the number of infants in each treatment condition in the monitor/potential delay category. |
| Birth Outcome: Gestational Age at Delivery | at delivery | Birth outcomes were obtained from the birth record. Gestational age was expressed in weeks. |
| Cost Per Participant | Trial entry through 24-weeks postpartum (approximately one year following smoking-cessation quit date). | Cost per participant for BP+FI and BP interventions. These costs per participant are used in calculation of the Incremental Cost Effectiveness Ratio (ICER). This ICER measure is the added healthcare sector cost per participant for BP+FI compared to BP relative to estimated net health gain per participant (QALY). Maternal net health gains in QALYs from cessation difference between treatment conditions at 24 weeks postpartum were based on Stapleton & West, 2012, Nicotine Tob Res; 14: 463-71. |
| Quality of Life Years Gained (QALYs) | 24 weeks postpartum | Smoking abstinence at the 24-week assessment was converted into quality of life years gained using standardized tables reported in Stapleton & West, 2012, Nicotine Tob Res; 14: 463-71. |
| Incremental Cost Effectiveness Ratio (ICER) | 24 weeks postpartum | A summary measure representing the economic value of an intervention (BP+FI) compared with an alternative (BP). The measure type used below is 'number' due to the fact that this measure is simply a ratio of mean dollars divided by mean years gained between the treatment conditions. Thus there was no alternative measure type that could be used or measure of dispersion available. |
| Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | at delivery | Compared the three trials conditions on preterm deliveries. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Additional Birth Outcome: Mean Birth Weight | at delivery | Birth weight was obtained for each infant from the birth record and expressed in grams. We report the group mean and standard error for each treatment condition. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Best Practices for Pregnant Smokers Five As plus referral to pregnancy-specific tobacco quit line
Best practices | 88 |
| Best Practices Plus Financial Incentives Best practices plus providing financial incentives contingent on biochemically verified abstinence. Incentives are in the form of vouchers exchangeable for retail items and available through 12-weeks postpartum.
Best practices
financial incentives: financial incentives provided contingent on biochemically confirmed smoking abstinence | 81 |
| Never-smoker Comparison Condition We will follow a group of never-smoker pregnant women matched to smokers on key sociodemographic and obstetrical characteristics for purposes of comparisons in birth/health outcomes at delivery and through 1 year postpartum | 80 |
| Total | 249 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Overall Study | Lost to Follow-up | 26 | 32 | 17 |
| Overall Study | Pregnancy termination . | 3 | 4 | 1 |
Baseline characteristics
| Characteristic | Best Practices for Pregnant Smokers | Total | Never-smoker Comparison Condition | Best Practices Plus Financial Incentives |
|---|---|---|---|---|
| Age, Continuous | 26.6 years STANDARD_DEVIATION 5.5 | 25.87 years STANDARD_DEVIATION 5.17 | 25.6 years STANDARD_DEVIATION 5 | 25.4 years STANDARD_DEVIATION 5 |
| Age started smoking (yrs) | 15.47 years STANDARD_DEVIATION 2.96 | 10.19 years STANDARD_DEVIATION 1.96 | 0 years STANDARD_DEVIATION 0 | 15.10 years STANDARD_DEVIATION 2.92 |
| % attempted to quit prepregnancy | 64 Participants | 121 Participants | 0 Participants | 57 Participants |
| Beck Depression Inventory total score | 12.8 units on a 0-63 scale STANDARD_DEVIATION 8.6 | 9.5 units on a 0-63 scale STANDARD_DEVIATION 7.1 | 5.8 units on a 0-63 scale STANDARD_DEVIATION 5.2 | 10.0 units on a 0-63 scale STANDARD_DEVIATION 7.4 |
| Cigarettes smoked per day at 1st antepartum visit | 9.92 cigarettes/day STANDARD_DEVIATION 6.18 | 6.30 cigarettes/day STANDARD_DEVIATION 3.8 | 0 cigarettes/day STANDARD_DEVIATION 0 | 8.99 cigarettes/day STANDARD_DEVIATION 5.21 |
| Cigarettes smoked per day pre-pregnancy | 18.27 cigarettes/day STANDARD_DEVIATION 9.42 | 12.51 cigarettes/day STANDARD_DEVIATION 6.43 | 0 cigarettes/day STANDARD_DEVIATION 0 | 19.25 cigarettes/day STANDARD_DEVIATION 9.87 |
| % endorsing that smoking will greatly harm baby | 70 Participants | 218 Participants | 79 Participants | 69 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 82 Participants | 228 Participants | 72 Participants | 74 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 6 Participants | 21 Participants | 8 Participants | 7 Participants |
| Fagerstrom Test for Nicotine Dependence | 4.33 0-10 scale STANDARD_DEVIATION 2.3 | 2.77 0-10 scale STANDARD_DEVIATION 1.46 | 0 0-10 scale STANDARD_DEVIATION 0 | 3.98 0-10 scale STANDARD_DEVIATION 2.07 |
| % living with other smokers | 68 Participants | 150 Participants | 18 Participants | 64 Participants |
| Minnesota Nicotine Withdrawal Scale total score; scale: 0 (none) to 4 (severe);average item scores | 1.60 scores on a scale STANDARD_DEVIATION 0.75 | 0.99 scores on a scale STANDARD_DEVIATION 0.5 | 0 scores on a scale STANDARD_DEVIATION 0 | 1.37 scores on a scale STANDARD_DEVIATION 0.76 |
| # quit attempts during pregnancy | 0.73 attempts STANDARD_DEVIATION 2.35 | 0.43 attempts STANDARD_DEVIATION 1.11 | 0 attempts STANDARD_DEVIATION 0 | 0.57 attempts STANDARD_DEVIATION 0.97 |
| Region of Enrollment United States | 88 participants | 249 participants | 80 participants | 81 participants |
| Sex: Female, Male Female | 88 Participants | 249 Participants | 80 Participants | 81 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Stress rating scale for past week from 0 (none) to 10 (extreme) | 6.3 Scores on a scale STANDARD_DEVIATION 2.2 | 4.9 Scores on a scale STANDARD_DEVIATION 2.3 | 3.3 Scores on a scale STANDARD_DEVIATION 2.1 | 5.0 Scores on a scale STANDARD_DEVIATION 2.5 |
| % with none or few family who smoke | 23 Participants | 105 Participants | 62 Participants | 20 Participants |
| % with no smoking allowed in home | 62 Participants | 190 Participants | 73 Participants | 55 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 91 | 0 / 85 | 0 / 81 |
| other Total, other adverse events | 0 / 91 | 0 / 85 | 0 / 81 |
| serious Total, serious adverse events | 3 / 91 | 4 / 85 | 1 / 81 |
Outcome results
Primary
7-day Point Prevalence Abstinence Levels at Final Antepartum Assessment
Abstinence was defined as woman reports that she has not smoked, not even a puff, in the past 7 days and self-report is biochemically verified via urine cotinine testing
Time frame: collected once per women at approximately 28-weeks gestation in each of the two smoking arms
Population: Comparison of women in two smoking-cessation arms
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Levels at Final Antepartum Assessment | 8 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Levels at Final Antepartum Assessment | 31 Participants |
Comparison: Hypothesized that women assigned to Best practices plus financial incentives would achieve greater abstinence than women assigned to Best practices only.p-value: <0.001Chi-squared
Secondary
7-day Point Prevalence Abstinence Postpartum
Compare two treatment arms on 7-day point-prevalence abstinence assessed at 2-, 4-, 8-, 12-, 24- and 48-weeks postpartum. Abstinence was defined as self-report of no smoking in past 7 days, not even a puff, with biochemical verification of self-report using urine cotinine testing
Time frame: Repeated assessments completed at 2-, 4-, 8-, 12-, 24-, and 48-weeks postpartum
Population: Hypothesized that women assigned to Best practices plus financial incentives would achieve greater smoking abstinence than women assigned to Best practices only.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Postpartum | 2 weeks postpartum | 17 Participants |
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Postpartum | 4 weeks postpartum | 14 Participants |
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Postpartum | 8 weeks postpartum | 12 Participants |
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Postpartum | 12 weeks postpartum | 10 Participants |
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Postpartum | 24 weeks postpartum | 11 Participants |
| Best Practices for Pregnant Smokers | 7-day Point Prevalence Abstinence Postpartum | 48 weeks postpartum | 10 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Postpartum | 24 weeks postpartum | 14 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Postpartum | 2 weeks postpartum | 31 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Postpartum | 12 weeks postpartum | 21 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Postpartum | 4 weeks postpartum | 30 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Postpartum | 48 weeks postpartum | 13 Participants |
| Best Practices Plus Financial Incentives | 7-day Point Prevalence Abstinence Postpartum | 8 weeks postpartum | 25 Participants |
p-value: <0.05Chi-squared
Comparison: Trial condition by assessment time interactionp-value: 0.003Mixed Models Analysis
Secondary
Ages & Stages Questionnaire (ASQ)
The ASQ assesses infant development in five areas (communication \[Comm\], gross motor \[GM\], fine motor \[FM\], problem solving \[PrbSlv\], personal-social \[PerSoc\]); Each area includes six items, each with a possible value of 0, 5, 10, along with a cutoff to dichotomize infants into typical/normal vs. monitor/potential delay categories for an area. Scores in each area are compared to norms; scores with 1 standard deviation of the norm mean are categorized as typical/normal and those greater than one standard deviation below the norm mean are categorized as monitor/potential delay. We report the dichotomized outcomes for each of the six areas at the 24-week and 48-week assessments noting the number of infants in each treatment condition in the monitor/potential delay category.
Time frame: 24- and 48-weeks postpartum
Population: Overall number of participants analyzed represents the number of participants for whom we obtained data on this outcome at 24-weeks postpartum; at 48-weeks the overall number analyzed were 69, 56, and 72 in Best Practices, Best Practices plus financial incentives, and never-smokers, respectively.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | Comm at 24-weeks | 1 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | Comm at 48-weeks | 2 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | GM at 24-weeks | 18 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | GM at 48-weeks | 14 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | FM at 24-weeks | 28 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | FM at 48-weeks | 7 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | PrbSlv at 24-weeks | 17 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | PrbSlv at 48-weeks | 10 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | PerSoc at 24-weeks | 15 Participants |
| Best Practices for Pregnant Smokers | Ages & Stages Questionnaire (ASQ) | PerSoc at 48-weeks | 11 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | PerSoc at 24-weeks | 9 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | Comm at 24-weeks | 2 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | FM at 48-weeks | 5 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | FM at 24-weeks | 17 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | Comm at 48-weeks | 0 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | PerSoc at 48-weeks | 8 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | PrbSlv at 48-weeks | 3 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | GM at 24-weeks | 10 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | PrbSlv at 24-weeks | 7 Participants |
| Best Practices Plus Financial Incentives | Ages & Stages Questionnaire (ASQ) | GM at 48-weeks | 6 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | PrbSlv at 48-weeks | 13 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | GM at 48-weeks | 13 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | FM at 24-weeks | 16 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | FM at 48-weeks | 7 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | PerSoc at 24-weeks | 13 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | PrbSlv at 24-weeks | 10 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | Comm at 24-weeks | 3 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | PerSoc at 48-weeks | 9 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | Comm at 48-weeks | 3 Participants |
| Never-smoker Comparison Condition | Ages & Stages Questionnaire (ASQ) | GM at 24-weeks | 10 Participants |
Secondary
Birth Outcome: Gestational Age at Delivery
Birth outcomes were obtained from the birth record. Gestational age was expressed in weeks.
Time frame: at delivery
Population: Birth outcomes were obtained from 88, 76, and 79 infants born to women in the best practices, best practices plus financial incentives, and never-smoker conditions.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Birth Outcome: Gestational Age at Delivery | 39.18 gestational age (weeks) | Standard Error 0.22 |
| Best Practices Plus Financial Incentives | Birth Outcome: Gestational Age at Delivery | 38.69 gestational age (weeks) | Standard Error 0.23 |
| Never-smoker Comparison Condition | Birth Outcome: Gestational Age at Delivery | 39.35 gestational age (weeks) | Standard Error 0.22 |
p-value: <0.05ANCOVA
Secondary
Birth Outcomes (NICU Admissions)
Compared three trial conditions on percent of NICU admissions
Time frame: at delivery
Population: Compared three trial conditions on NICU admissions.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Birth Outcomes (NICU Admissions) | NICU admitted | 11 Participants |
| Best Practices for Pregnant Smokers | Birth Outcomes (NICU Admissions) | no NICU | 77 Participants |
| Best Practices Plus Financial Incentives | Birth Outcomes (NICU Admissions) | NICU admitted | 10 Participants |
| Best Practices Plus Financial Incentives | Birth Outcomes (NICU Admissions) | no NICU | 66 Participants |
| Never-smoker Comparison Condition | Birth Outcomes (NICU Admissions) | NICU admitted | 11 Participants |
| Never-smoker Comparison Condition | Birth Outcomes (NICU Admissions) | no NICU | 68 Participants |
p-value: <0.05Chi-squared
Secondary
Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries)
Compared the three trials conditions on preterm deliveries.
Time frame: at delivery
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | preterm | 6 Participants |
| Best Practices for Pregnant Smokers | Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | >/= 37 weeks | 82 Participants |
| Best Practices Plus Financial Incentives | Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | preterm | 10 Participants |
| Best Practices Plus Financial Incentives | Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | >/= 37 weeks | 66 Participants |
| Never-smoker Comparison Condition | Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | preterm | 6 Participants |
| Never-smoker Comparison Condition | Birth Outcomes (Percent Preterm [<37 Weeks] Deliveries) | >/= 37 weeks | 73 Participants |
p-value: <0.05Chi-squared
Secondary
Birth Outcomes (% Small for Gestational Age Deliveries)
Birth outcomes were compared between the three study arms. Small for gestational age was defined as \<10th percentile using INTERGROWTH-21st \[2021\] https://intergrowth21.tghn.org/about/about-us/.
Time frame: delivery
Population: Comparison of three trial conditions on SGA deliveries
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Birth Outcomes (% Small for Gestational Age Deliveries) | Small for Gestational Age | 16 Participants |
| Best Practices for Pregnant Smokers | Birth Outcomes (% Small for Gestational Age Deliveries) | Normal size for gestational age | 72 Participants |
| Best Practices Plus Financial Incentives | Birth Outcomes (% Small for Gestational Age Deliveries) | Small for Gestational Age | 8 Participants |
| Best Practices Plus Financial Incentives | Birth Outcomes (% Small for Gestational Age Deliveries) | Normal size for gestational age | 68 Participants |
| Never-smoker Comparison Condition | Birth Outcomes (% Small for Gestational Age Deliveries) | Small for Gestational Age | 2 Participants |
| Never-smoker Comparison Condition | Birth Outcomes (% Small for Gestational Age Deliveries) | Normal size for gestational age | 77 Participants |
p-value: 0.01Regression, Logistic
Secondary
Breastfeeding in the Three Trial Arms
Compare the three trial arms on overall percentage of women continuing to breastfeed at repeated postpartum assessments
Time frame: Repeated assessments completed at 2-, 4-, 8-, 12-, 24-, and 48-weeks postpartum
Population: Breastfeeding data were not obtained on all women. The number of women with at least one assessment with breastfeeding data in each group is: Best practices = 79, Best practices plus financial incentives = 69, Never-Smokers = 78
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Breastfeeding in the Three Trial Arms | 2-weeks postpartum | 49 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding in the Three Trial Arms | 4-weeks postpartum | 40 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding in the Three Trial Arms | 8-weeks postpartum | 34 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding in the Three Trial Arms | 12-weeks postpartum | 28 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding in the Three Trial Arms | 24-weeks postpartum | 21 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding in the Three Trial Arms | 48-weeks postpartum | 9 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding in the Three Trial Arms | 48-weeks postpartum | 9 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding in the Three Trial Arms | 2-weeks postpartum | 50 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding in the Three Trial Arms | 12-weeks postpartum | 28 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding in the Three Trial Arms | 24-weeks postpartum | 21 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding in the Three Trial Arms | 4-weeks postpartum | 40 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding in the Three Trial Arms | 8-weeks postpartum | 34 Participants |
| Never-smoker Comparison Condition | Breastfeeding in the Three Trial Arms | 4-weeks postpartum | 56 Participants |
| Never-smoker Comparison Condition | Breastfeeding in the Three Trial Arms | 8-weeks postpartum | 48 Participants |
| Never-smoker Comparison Condition | Breastfeeding in the Three Trial Arms | 48-weeks postpartum | 23 Participants |
| Never-smoker Comparison Condition | Breastfeeding in the Three Trial Arms | 12-weeks postpartum | 43 Participants |
| Never-smoker Comparison Condition | Breastfeeding in the Three Trial Arms | 2-weeks postpartum | 59 Participants |
| Never-smoker Comparison Condition | Breastfeeding in the Three Trial Arms | 24-weeks postpartum | 36 Participants |
Comparison: Interaction of trial condition and timep-value: 0.48Mixed Models Analysis
Secondary
Breastfeeding While Abstinent From Smoking
We compared the three trial arms on the percent of women who reported breastfeeding and were biochemically confirmed to be abstinent from smoking at each postpartum assessment.
Time frame: Repeated assessments completed at 2-, 4-, 8-, 12-, 24-, and 48-weeks postpartum
Population: Comparing women in each trial condition who reported breastfeeding and were biochemically confirmed abstinent from smoking at each postpartum assessment. Breastfeeding data were not obtained on all women. The number of women with at least one assessment with breastfeeding data in each group is: Best practices = 79, Best practices plus financial incentives = 69, Never-Smokers = 78
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Breastfeeding While Abstinent From Smoking | 2-weeks postpartum | 15 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding While Abstinent From Smoking | 4-weeks postpartum | 11 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding While Abstinent From Smoking | 8-weeks postpartum | 9 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding While Abstinent From Smoking | 12-weeks postpartum | 7 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding While Abstinent From Smoking | 24-weeks postpartum | 7 Participants |
| Best Practices for Pregnant Smokers | Breastfeeding While Abstinent From Smoking | 48-weeks postpartum | 3 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding While Abstinent From Smoking | 48-weeks postpartum | 5 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding While Abstinent From Smoking | 2-weeks postpartum | 29 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding While Abstinent From Smoking | 12-weeks postpartum | 15 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding While Abstinent From Smoking | 24-weeks postpartum | 9 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding While Abstinent From Smoking | 4-weeks postpartum | 24 Participants |
| Best Practices Plus Financial Incentives | Breastfeeding While Abstinent From Smoking | 8-weeks postpartum | 19 Participants |
| Never-smoker Comparison Condition | Breastfeeding While Abstinent From Smoking | 4-weeks postpartum | 56 Participants |
| Never-smoker Comparison Condition | Breastfeeding While Abstinent From Smoking | 8-weeks postpartum | 48 Participants |
| Never-smoker Comparison Condition | Breastfeeding While Abstinent From Smoking | 48-weeks postpartum | 23 Participants |
| Never-smoker Comparison Condition | Breastfeeding While Abstinent From Smoking | 12-weeks postpartum | 43 Participants |
| Never-smoker Comparison Condition | Breastfeeding While Abstinent From Smoking | 2-weeks postpartum | 59 Participants |
| Never-smoker Comparison Condition | Breastfeeding While Abstinent From Smoking | 24-weeks postpartum | 36 Participants |
Comparison: Examining main effect of treatment condition.p-value: <0.0001Mixed Models Analysis
Comparison: Testing interaction of treatment condition and assessment timep-value: 0.89Mixed Models Analysis
Secondary
Cost Per Participant
Cost per participant for BP+FI and BP interventions. These costs per participant are used in calculation of the Incremental Cost Effectiveness Ratio (ICER). This ICER measure is the added healthcare sector cost per participant for BP+FI compared to BP relative to estimated net health gain per participant (QALY). Maternal net health gains in QALYs from cessation difference between treatment conditions at 24 weeks postpartum were based on Stapleton & West, 2012, Nicotine Tob Res; 14: 463-71.
Time frame: Trial entry through 24-weeks postpartum (approximately one year following smoking-cessation quit date).
Population: All participants treated in best practices plus financial incentives and best practices trial conditions.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Cost Per Participant | 23007.01 U.S. dollars | Standard Error 1284.83 |
| Best Practices Plus Financial Incentives | Cost Per Participant | 22372.25 U.S. dollars | Standard Error 1594.23 |
Secondary
Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS).
The craving item is on a 0 (none) to 4 (severe) scale. We report mean (SEM) scores.
Time frame: Outcomes reported for 8 assessments (early pregnancy, late pregnancy, 2, 4, 8, 12, 24, 28 weeks postpartum.
Population: Comparing between women assigned to the two smoking-cessation trial conditions.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 4 weeks postpartum | 2.17 scores on a scale | Standard Error 0.15 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | early antepartum | 2.73 scores on a scale | Standard Error 0.14 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | late antepartum | 2.30 scores on a scale | Standard Error 0.14 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 2 weeks postpartum | 2.14 scores on a scale | Standard Error 0.15 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 8 weeks postpartum | 2.27 scores on a scale | Standard Error 0.15 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 12 weeks postpartum | 2.33 scores on a scale | Standard Error 0.14 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 24 weeks postpartum | 1.97 scores on a scale | Standard Error 0.15 |
| Best Practices for Pregnant Smokers | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 48 weeks postpartum | 2.10 scores on a scale | Standard Error 0.16 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 48 weeks postpartum | 1.99 scores on a scale | Standard Error 0.17 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 8 weeks postpartum | 1.75 scores on a scale | Standard Error 0.16 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | early antepartum | 1.75 scores on a scale | Standard Error 0.15 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 24 weeks postpartum | 1.97 scores on a scale | Standard Error 0.16 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | late antepartum | 1.52 scores on a scale | Standard Error 0.15 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 12 weeks postpartum | 1.72 scores on a scale | Standard Error 0.16 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 2 weeks postpartum | 1.39 scores on a scale | Standard Error 0.16 |
| Best Practices Plus Financial Incentives | Craving Item From the Minnesota Nicotine Withdrawal Scale (MNWS). | 4 weeks postpartum | 1.55 scores on a scale | Standard Error 0.16 |
p-value: <0.001Mixed Models Analysis
Secondary
Incremental Cost Effectiveness Ratio (ICER)
A summary measure representing the economic value of an intervention (BP+FI) compared with an alternative (BP). The measure type used below is 'number' due to the fact that this measure is simply a ratio of mean dollars divided by mean years gained between the treatment conditions. Thus there was no alternative measure type that could be used or measure of dispersion available.
Time frame: 24 weeks postpartum
Population: Treatment conditions were combined because the ICER outcome is a measure of the economic benefit of the BP+FI intervention relative to the BP comparator.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Best Practices for Pregnant Smokers | Incremental Cost Effectiveness Ratio (ICER) | 23511 dollars per years gained |
Secondary
Infant Growth in First Year of Life
Infant growth (length & weight) expressed a Body Mass Index (BMI) percentile score was assessed at delivery, 24- and 48-week postpartum assessments.
Time frame: delivery, 24-week, and 50-week postpartum assessments
Population: There was data available for one or more assessments for 79, 67, and 77 of infants born to mothers in the Best practices, Best practices plus financial incentives, and never-smoker conditions. We compared body mass index (BMI) percentile scores between infants from the three trial conditions at delivery, 24-weeks postpartum, and 48-weeks postpartum.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Best Practices for Pregnant Smokers | Infant Growth in First Year of Life | 24-weeks postpartum | 56.19 BMI Percentile | Standard Error 3.36 |
| Best Practices for Pregnant Smokers | Infant Growth in First Year of Life | Birth | 31.39 BMI Percentile | Standard Error 3.35 |
| Best Practices for Pregnant Smokers | Infant Growth in First Year of Life | 48-weeks postpartum | 65.97 BMI Percentile | Standard Error 3.73 |
| Best Practices Plus Financial Incentives | Infant Growth in First Year of Life | 24-weeks postpartum | 59.14 BMI Percentile | Standard Error 3.71 |
| Best Practices Plus Financial Incentives | Infant Growth in First Year of Life | Birth | 34.92 BMI Percentile | Standard Error 3.51 |
| Best Practices Plus Financial Incentives | Infant Growth in First Year of Life | 48-weeks postpartum | 65.69 BMI Percentile | Standard Error 4.06 |
| Never-smoker Comparison Condition | Infant Growth in First Year of Life | Birth | 40.56 BMI Percentile | Standard Error 3.2 |
| Never-smoker Comparison Condition | Infant Growth in First Year of Life | 48-weeks postpartum | 66.62 BMI Percentile | Standard Error 3.47 |
| Never-smoker Comparison Condition | Infant Growth in First Year of Life | 24-weeks postpartum | 46.15 BMI Percentile | Standard Error 3.39 |
p-value: 0.009Mixed Models Analysis
Secondary
Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions.
Reporting mean total scores and SEM from the Minnesota Nicotine Withdrawal Scale (MNWS). Total score is an average of 7 items, with each item on a 0 (none) to 4 (severe) scale.
Time frame: Outcomes reported for 8 assessments (early pregnancy, late pregnancy, 2, 4, 8, 12, 24, 28 weeks postpartum.
Population: Comparing women assigned to the two smoking-cessation trial conditions.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | Early antepartum | 1.47 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | Late antepartum | 1.38 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 2-weeks postpartum | 0.80 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 4-weeks postpartum | 0.80 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 8-weeks postpartum | 0.92 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 12-weeks postpartum | 0.86 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 24-weeks postpartum | 0.81 scores on a scale | Standard Error 0.08 |
| Best Practices for Pregnant Smokers | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 48-weeks postpartum | 1.03 scores on a scale | Standard Error 0.8 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 48-weeks postpartum | 0.84 scores on a scale | Standard Error 0.09 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | Early antepartum | 1.02 scores on a scale | Standard Error 0.08 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 8-weeks postpartum | 0.68 scores on a scale | Standard Error 0.08 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | Late antepartum | 0.93 scores on a scale | Standard Error 0.08 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 24-weeks postpartum | 0.78 scores on a scale | Standard Error 0.09 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 2-weeks postpartum | 0.70 scores on a scale | Standard Error 0.09 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 12-weeks postpartum | 0.59 scores on a scale | Standard Error 0.08 |
| Best Practices Plus Financial Incentives | Nicotine Withdrawal Total Scores for the Two Smoking-cessation Trial Conditions. | 4-weeks postpartum | 0.68 scores on a scale | Standard Error 0.09 |
Comparison: Examine interaction of treatment condition and assessment time.p-value: <0.001ANCOVA
p-value: <0.001Mixed Models Analysis
Secondary
Quality of Life Years Gained (QALYs)
Smoking abstinence at the 24-week assessment was converted into quality of life years gained using standardized tables reported in Stapleton & West, 2012, Nicotine Tob Res; 14: 463-71.
Time frame: 24 weeks postpartum
Population: Analysis of results for this measure cannot be reported separately for each treatment arm. Thus, treatment conditions were combined because the outcome is the difference in quality of life years gained (QALYs) between conditions.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Quality of Life Years Gained (QALYs) | 0.0267 net years gained | Standard Deviation 0.0412 |
Other Pre-specified
Additional Birth Outcome: Mean Birth Weight
Birth weight was obtained for each infant from the birth record and expressed in grams. We report the group mean and standard error for each treatment condition.
Time frame: at delivery
Population: Birth outcomes were obtained for 88, 76, and 79 infants of mothers in best practices, best practices plus financial incentives, and never-smokers.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Best Practices for Pregnant Smokers | Additional Birth Outcome: Mean Birth Weight | 3176.39 weight (grams) | Standard Error 46.74 |
| Best Practices Plus Financial Incentives | Additional Birth Outcome: Mean Birth Weight | 3214.84 weight (grams) | Standard Error 50.11 |
| Never-smoker Comparison Condition | Additional Birth Outcome: Mean Birth Weight | 3391.14 weight (grams) | Standard Error 49.64 |
p-value: 0.006ANCOVA