Project Duration
February 2006 – October 2012
Funder
NHS Health Technology Assessment Programme (HTA)
Project Staff
- Prof Tim Coleman (PI) 1
- Prof Jim Thornton 1
- Prof John Britton 1
- Prof Sarah Lewis 1
- Dr Kim Watts 1
- Prof Michael Coughtrie 2
- Claire Mannion 3
- Prof Neil Marlow 4
- Prof Christine Godfrey 5
Staff Institutions
- The University of Nottingham
- University of Dundee
- Central Cheshire PCT, Cheshire
- University College London
- University of York
Aims
The overall aim of the study wasto investigate whether NRT is more effective than placebo in achieving smoking cessation for women between 12 and 24 weeks pregnant, who currently smoke five or more cigarettes daily and who smoked at least ten cigarettes daily before pregnancy.
Methods
Randomised, placebo–controlled, parallel-group trial and economic evaluation with follow-up at 4 weeks after randomisation, delivery, and until infants were 2 years old. Randomisation was stratified by centre, and a computer-generated sequence was used to allocate participants. Participants, site pharmacies and all study staff were blind to treatment allocation.
Outcomes
NRT patches had no enduring, significant effect on smoking in pregnancy; however, 2-year-olds born to women who used NRT were more likely to have survived without any developmental impairment. Further studies should investigate the effectiveness and safety of higher doses of NRT.
Findings
1050 women enrolled (521 NRT, 529 placebo). There were 1010 live singleton births, and 12 participants had live twins; there were 14 fetal deaths and no birth data for 14 participants. Numbers of adverse pregnancy and birth outcomes were similar in trial groups.
Smoking: All participants were included in the intention to treat analyses; those lost to follow up (7% for primary outcome) were assumed to be smoking. At 1 month after randomisation, the validated cessation rate was higher in the NRT group [21.3% versus 11.7%, OR (95% CI) for cessation with NRT, 2.05 (1.46-2.88)]. At delivery there was no difference between groups’ smoking cessation rates: 9.4% in the NRT and 7.6% in the placebo group [OR (95% CI), 1.26 (0.82 to 1.96)].
Infants: At 2 years, analyses were based on data from 890 singleton infants (88.1%; 445 NRT, 446 placebo) and used multiple imputation. In the NRT group 77.6% (323) had no impairment compared to 65.0% (290) in placebo [OR, (95% CI) 1.39 (1.04-1.85).
The incremental cost effectiveness ratio for NRT use was £4,156 per quitter (£4,926 including twins), but there was substantial uncertainty around these estimates.
Stage of development
Completed October 2012
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Publications
The protocol for the study has been published and can be found via open access at: www.biomedcentral.com/
1472-6963/7/2
The primary outcome findings can be found in the following New England Journal of Medicine publication:
Coleman T, Cooper S, Thornton J, Grainge M, Watts K,Britton J and Lewis S (2012) Double-blind, randomised, placebo-controlled trial of nicotine replacement therapy patches in pregnancy: the SNAP Trial. New England Journal of Medicine 366 (9) 808-818
Coleman T, Thornton J, Britton J, Lewis S, Watts K, Coughtrie M, Mannion C, Marlow N, Godfrey C (2007) Protocol for the Smoking, Nicotine, and Pregnancy (SNAP) trial: double-blinded, placebo-randomised, controlled trial of nicotine replacement therapy in pregnancy. BMC Health Services Research Vol 7:2.
http://www.biomedcentral.com/1472-6963/7/2
Contact for further information
Kim Watts