The Cessation in Pregnancy Incentives Trial (CPIT): A phase II randomised controlled trial

CPIT is a randomised control trial (RCT) examining the effectiveness of financial incentives to help pregnant women stop smoking.  To find out if financial incentives encourage pregnant smokers to attend the NHS stop smoking cessation services and/or to quit smoking during pregnancy the study will offer one group of women financial incentives as well as standard care and the other group standard care alone.  The primary outcome will be validated abstinence towards the end of pregnancy.

Those pregnant smokers randomly placed in the incentive group could receive financial payments totalling £400:

• £50 for attending a first face to face appointment with an NHS Smokefree Pregnancy advisor and setting a quit date
• £50 for being smokefree 4 weeks after quit date
• £100 validated for being smokefree 12 weeks after quit date
• £200 for being smokefree towards the end of pregnancy (at around 36 weeks gestation or when about 8 months pregnant).

These will be store vouchers which can be exchanged at many normal shop outlets.

The research questions

1. What is likely therapeutic efficacy of financial incentives to encourage women to attend specialist cessation services, to set a quit date, to quit smoking and be abstinent towards the end of pregnancy?
2. Are incentives potentially cost-effective to help pregnant women to stop smoking?
3. Can incentives be introduced in a way that is feasible and acceptable to women and service providers and are there any unintended consequences?
4. What other factors need to be considered in designing a phase III RCT to follow on from this phase II trial?

Study design

The study has 3 elements:

1. Randomised Controlled Trial (Phase II)
2. Health economics anaylsis
3. Interviews with pregnant smokers and members of staff

Setting: NHS Greater Glasgow & Clyde Health Board

Target population: Pregnant smokers living in the NHS Greater Glasgow & Clyde Board area.

Data collection

Data will be collected at the following time points:

Informed consent to join trial:

• socio-demographic data
• smoking behaviour

At first face to face appointment and setting of quit date:

• smoking cessation assessment
• quit date
• nicotine replacement therapy risk factor assessment

At 4 and 12 weeks post quit date:

• self report and CO validated smoking status

At the end of pregnancy:

• self reported and CO validated smoking status
• biochemical validated smoking status

Following childbirth:

• gestation
• birth weight