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Trial registered on ANZCTR


Registration number
ACTRN12615001158550
Ethics application status
Approved
Date submitted
17/02/2015
Date registered
30/10/2015
Date last updated
30/07/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Supporting expectant mothers to quit smoking
Scientific title
Promoting smoking cessation in pregnant smokers: Quit contingent participant and partner vouchers to motivate long term cessation.
Secondary ID [1] 286188 0
Nil
Universal Trial Number (UTN)
Trial acronym
SEMQ
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Tobacco smoking in pregnancy 294217 0
Condition category
Condition code
Reproductive Health and Childbirth 294536 294536 0 0
Normal pregnancy
Mental Health 294537 294537 0 0
Addiction
Reproductive Health and Childbirth 296400 296400 0 0
Antenatal care

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
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").

Intervention code [1] 291202 0
Treatment: Other
Intervention code [2] 293064 0
Behaviour
Comparator / control treatment
Control group participants will be informed 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 (using CO monitor, value 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, and perceived partner support. Additionally, researchers will contact participants monthly during the study (over approximately a 12 month period, from study enrolment antepartum – 6 months postpartum) via telephone to determine 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 smoking status and receive the quit contingent incentive. 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 (see details in intervention description). All participants will be provided with quit materials and a ‘Partner Pack’ which will provide their ‘quit buddy’ with useful resources for supporting the participant's quit attempt.

Data from the 'historical' control group will be obtained from the Tasmanian Council of Obstetric and Paediatric Morbidity and Mortality (COPMM) data sets, published in a yearly report by the Tasmanian Dept of Health and Human Services. Data relating to a range of perinatal clinical indices, including drug and alcohol use, is routinely collected from all pregnant women in Tasmania. The historical data on smoking prevalence intra- and post-partum, collected between May 2013 and Oct 2014 (a 17 month time period as per the SEMQ study), will enable a comparison to be made of the efficacy of the study intervention (financial incentives) in enhancing smoking cessation rates during pregnancy when compared to the prevalence rates seen in response to "usual care" smoking cessation interventions used historically in the Tasmanian public hospital antenatal setting.

Control group
Active

Outcomes
Primary outcome [1] 294316 0
The percentage of women receiving antenatal care (statewide), who quit smoking during pregnancy (first 20 weeks vs second 20 weeks) in the study timeframe (2015-2016, see below), will be compared to the percentage in previous years (based on historical data e.g., 2012, 2011, 2010 antenatal data provided by DHHS).
Note: recruitment commenced in May 2015 in the North and North West of Tasmania, and in Sept 2015 at the Royal Hobart Hospital and services in the south of the state. Recruitment will conclude in Sept 2016.

This outcome (smoking cessation) will be assessed by biochemical verification of the expectant woman's self-reported smoking status, via exhaled breath Carbon Monoxide (CO) measurement. A threshold value of 7ppm will discriminate smoking status, with 0-6ppm indicating non-smoking status and greater than or equal to 7ppm indicating current smoking.
Timepoint [1] 294316 0
17 months following start of study recruitment.
Primary outcome [2] 294317 0
Primary outcome 2 (the effect of incentivised partner support in facilitating maternal smoking cessation) will be measured by comparing the proportion/percentage of women verified (via CO monitor and self-report) as quit at end of pregnancy (~8 months gestation) and postpartum (2 and 12 months postpartum) in the control (pregnant smoker incentivised) compared to treatment group (both pregnant woman and partner incentivised).
Timepoint [2] 294317 0
This outcome will be measured at: (i) end of pregnancy (~8 months gestation; V2), (ii) two months postpartum (V3), and (iii) 12 months postpartum. These time points will occur at approximately 5 , 8 and 18 months, respectively, post study enrolment.
Secondary outcome [1] 313019 0
The quality of partner interaction, and it's influence on maternal smoking cessation (secondary outcome 1), will be evaluated by comparing the Partner Interaction Questionnaire (PIQ) score ratios at three time points (see below) between those women biochemically verified as having quit smoking compared with those self-reporting as not quit.
Note: a high ratio PIQ score indicates that the woman has reported a greater number of positive compared to negative support behaviours from the partner).
Timepoint [1] 313019 0
This outcome will be measured at 3 time points: (i) end of pregnancy (~8 months gestation; V2), (ii) two months postpartum (V3), and (iii) 12 months postpartum.
These time points will occur at approximately 5 , 8 and 18 months, respectively, post study enrolment.

Eligibility
Key inclusion criteria
Pregnant (> 16 years of age)
Current smoker (using Prenatal Screening Guide)
Attending any statewide public hospital antenatal service (either clinic-based service or outreach midwifery service) for routine antenatal care
Minimum age
16 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Non-smoker (using Prenatal Screening Guide)
Cognitive or intellectual impairment that renders the participant unable to complete the participation requirements (e.g., completion of surveys, attend organised study appointments)

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will be recruited from the antenatal units (i.e., both clinic-based and outreach services) of statewide public hospitals in Tasmania (Launceston General Hospital, Royal Hobart Hospital, North West Regional Hospital). Antenatal staff (O&G physicians, registrars, and midwives) will provide study information (in the form of a flyer) to eligible participants during antenatal appointments (i.e., to pregnant women who answer ‘yes’ to the routine question of ‘whether the mother smoked a cigarette at any time during the first 20 weeks of the pregnancy’). Potential participants will then contact the researcher (phone or email) if they are interested in participating. Researchers will screen potential participants to determine eligibility using a set protocol, which is based on a published, best-practice protocol (Melvin & Tucker, 2000). This screening process will involve a more detailed assessment of smoking status and participant eligibility.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants recruited in the first three months (location dependent, e.g. LGH: May, June, July 2015; RHH: Sept, Oct, Nov 2015) will be allocated to the control group (CG). Participants recruited in the following three months will be allocated to the treatment group (TG). Recruitment for the next 14 months will follow the same pattern. An ABAB design is more appropriate than a fully randomised, parallel group controlled trial since there is great potential for the women recruited, due to the small sample pool, to know each other or discuss their participation in the study during routine antenatal classes and appointments (particularly in the case of the smaller regional hospitals, e.g., LGH, Mersey Hospital). Which phase of the ABAB design participants are being recruited to will be known only by the research team. This way, potential bias in the way antenatal care is delivered to the two research groups will be avoided.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Other
Other design features
The ABAB parallel design was specifically chosen to help optimise participant blinding. Given the relatively small population of Tasmania, and particularly the regional centres and small regional hospitals from which study participants will be recruited, there is a high likelihood that participants will know or encounter other individuals enrolled in the study.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
To determine if incentivised partner support (and incentives in general) are more effective than usual care, the percentage of women who quit during antenatal care (indicated by smoking in first 20 weeks of pregnancy, but having quit in the second 20 weeks of pregnancy) in 2015 (for 12 months of the study intervention) will be compared with historical cohort data (including 2012, as well as 2011-2005; data provided by DHHS). Using sample sizes of 200 (2015) and 260 (2011 – greater numbers expected in previous cohorts), there would be power of 0.88 to detect a small to medium effect size of 0.3. However we anticipate a larger effect size (see Donatelle et al., 2000 reference below), especially since less than 1% quit during pregnancy under usual care treatment in 2011 (DHHS, 2012).

To determine if incentivised partner support is more effective than incentives only, Treatment and Control Group abstinence rates at end of pregnancy (~8 months gestation, V2), 2-months postpartum (V3) and 12 months postpartum will be compared using the chi-square test. Whilst no study to our knowledge has compared participant incentive with participant plus partner incentive, Donatelle et al. (2000) compared a usual care control group with an incentive plus partner incentive treatment group and found that at the end of pregnancy, 32% of treatment group participants (n=105) had quit compared with 9% in the control group (n=102), with a large effect size found (chi-square = 18.4, n=207, d=0.62). Since the control group in the present study will also be receiving incentives, it is anticipated that the effect size will be moderate, rather than large. As such, to determine if there is a significant difference between treatment and control quit rates at the end of pregnancy (and postpartum), with the power of .80 to detect an effect size of .30, the study will require a total sample size of 108. Since it is anticipated that data will be obtained from 200 women, even with attrition, this sample size should be sufficient to detect the anticipated effect size.

To determine if quality of support determines abstinence, participants, regardless of group allocation (Treatment vs Control) will be regrouped to either PIQ-POS or PIQ-NEG, as determined by the ratio of positive compared to negative support they report receiving from their partners. The PIQ-POS and PIQ-NEG smoking abstinence rates (%) at the three time points (end of pregnancy, 2 months postpartum, and 12 month postpartum) will be compared. To our knowledge, this is the only study to compare partner support (PIQ20) received from incentivised and non-incentivised partners, and thus it is not known exactly what effect size to expect. Furthermore, to our knowledge, only underpowered pilot studies have compared social support with a control. Cohen and Lichtenstein’s (1990) study found female quitters (ratio = 4.08, n=155) reported receiving significantly more partner support compared to male quitters (ratio = 2.60, n=66), t(167) = 2.03, p <.04, d = 0.31, r = 0.16. If this is used as a guide, independent samples t-test to compare the ratio of positive to negative partner support behaviours received by women in the Treatment versus Control group, with power of .80, to detect an effect size of .30, would require a sample of n= 278 (139/139) + 10% ~306. Since the present study will provide a voucher incentive to treatment group partners to be effective quit buddies, we expect a larger effect size. As such, to detect a medium to large effect of.40, we would require a total sample size of n=156 (78/78). By over recruiting 10% to account for attrition, we would require a sample size of ~n = 172.



Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
TAS
Recruitment hospital [1] 3461 0
Launceston General Hospital - Launceston
Recruitment hospital [2] 4483 0
Royal Hobart Hospital - Hobart
Recruitment hospital [3] 4491 0
Mersey Community Hospital - Latrobe
Recruitment hospital [4] 4492 0
North West Regional Hospital - Burnie
Recruitment postcode(s) [1] 9232 0
7250 - Launceston
Recruitment postcode(s) [2] 10668 0
7000 - Hobart
Recruitment postcode(s) [3] 10684 0
7307 - Latrobe
Recruitment postcode(s) [4] 10685 0
7320 - Burnie

Funding & Sponsors
Funding source category [1] 290760 0
Charities/Societies/Foundations
Name [1] 290760 0
Cancer Council Tasmania
Country [1] 290760 0
Australia
Funding source category [2] 292242 0
University
Name [2] 292242 0
University of Tasmania, Faculty of Health Fellowship
Country [2] 292242 0
Australia
Primary sponsor type
Individual
Name
Dr Mai Frandsen
Address
School of Health Sciences
University of Tasmania
Locked Bag 1322
Launceston, Tasmania, 7250
Country
Australia
Secondary sponsor category [1] 289447 0
Individual
Name [1] 289447 0
Dr Stuart Ferguson
Address [1] 289447 0
School of Pharmacy
Private Bag 26
University of Tasmania
Hobart, Tasmania, 7001
Country [1] 289447 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292392 0
Human Research Ethics Committee (Tasmania) Network
Ethics committee address [1] 292392 0
Ethics committee country [1] 292392 0
Australia
Date submitted for ethics approval [1] 292392 0
10/11/2014
Approval date [1] 292392 0
11/02/2015
Ethics approval number [1] 292392 0
H0014568

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes
Attachments [2] 589 589 0 0
Attachments [4] 602 602 0 0
Attachments [7] 605 605 0 0
Attachments [11] 610 610 0 0

Contacts
Principal investigator
Name 54982 0
Dr Dr Mai Frandsen
Address 54982 0
School of Health Sciences
University of Tasmania
Locked Bag 1322
Launceston Tas 7250
Country 54982 0
Australia
Phone 54982 0
+61428364819
Fax 54982 0
Email 54982 0
Mai.Frandsen@utas.edu.au
Contact person for public queries
Name 54983 0
Mai Frandsen
Address 54983 0
School of Health Sciences
University of Tasmania
Locked Bag 1322
Launceston Tas 7250
Country 54983 0
Australia
Phone 54983 0
+61428364819
Fax 54983 0
Email 54983 0
Mai.Frandsen@utas.edu.au
Contact person for scientific queries
Name 54984 0
Mai Frandsen
Address 54984 0
School of Health Sciences
University of Tasmania
Locked Bag 1322
Launceston Tas 7250
Country 54984 0
Australia
Phone 54984 0
+61428364819
Fax 54984 0
Email 54984 0
Mai.Frandsen@utas.edu.au

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