Journal of Smoking Cessation


Characterising the ‘Txt2Stop’ Smoking Cessation Text Messaging Intervention in Terms of Behaviour Change Techniques

Susan Michiea1 c1, Caroline Freea2 and Robert Westa3

a1 Department of Clinical, Educational and Health Psychology, University College London, UK

a2 Clinical Trials Research Unit, London School of Hygiene and Tropical Medicine, UK

a3 Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK


The ‘Txt2Stop’ SMS messaging programme has been found to double smokers’ chances of stopping. It is important to characterise the content of this information in terms of specific behaviour change techniques (BCTs) for the purpose of future development. This study aimed to (i) extend a proven system for coding BCTs to text messaging and (ii) characterise Txt2Stop using this system. A taxonomy previously used to specify BCTs in face-to-face behavioural support for smoking cessation was adapted for the Txt2Stop messages and inter-rater reliability for the adapted system assessed. The system was then applied to all the messages in the Txt2Stop programme to determine its profile in terms of BCTs used. The text message taxonomy comprised 34 BCTs. Inter-rater reliability was moderate, reaching a ceiling of 61% for the core program messages with all discrepancies readily resolved. Of 899 texts delivering BCTs, 218 aimed to maintain motivation to remain abstinent, 870 to enhance self-regulatory capacity or skills, 39 to promote use of adjuvant behaviours such as using stop-smoking medication, 552 to maintain engagement with the intervention and 24 were general communication techniques. The content of Txt2Stop focuses on helping smokers with self-regulation and maintaining engagement with the intervention. The intervention focuses to a lesser extent on boosting motivation to remain abstinent; little attention is given to promoting effective use of adjuvant behaviours such as use of nicotine replacement therapy. As new interventions of this kind are developed it will be possible to compare their effectiveness and relate this to standardised descriptions of their content using this system.


  • smoking cessation;
  • digital interventions;
  • text messaging;
  • behaviour change techniques;
  • behavioural intervention;
  • mobile phone


c1 Address for correspondence: Susan Michie, Department of Clinical, Educational and Health Psychology, 1–19 Torrington Place, University College London, London WC1E 7HB, UK. Email: