Seven (purposive) interventions have used habit formation in either capacity.
Only formation studies, which focus on participants undergoing natural or purposive interventions to create new habits, are available (Fleig et al., 2013; Judah et al., 2013; Lally et al., 2010).
Consecutive, consenting physicians (convenience sampling) were recruited to represent both professions and different hospitals in a variety of health regions exposed to the three interventions (purposive sampling).
In each country the sampling framework was purposive, focusing on the intervention and non-intervention districts of the QUALMAT study, and on primary level facilities.
To apply the framework and tools thus developed to quantify the changes in travel behaviour, physical activity and carbon emissions and changes in putative mediating factors associated with infrastructural interventions at a purposive sample of case study Connect2 sites and to explore why these interventions are (or are not) effective, in what ways, for whom and in what circumstances.
Twenty participants will be recruited from those allocated to the intervention group using purposive sampling initially and theoretical sampling later on (guided by data analysis) to ensure diversity of experiences.
Following this pilot, the main RCT took place complemented by a parallel qualitative evaluation of the intervention with a purposive sample of patients (n = 67), practitioners (n = 26) and research nurses (n = 4) (Corrigan M, D'Eath M, Cupples ME, Wilson J, Murphy AW.
Purposive sampling was used to select three intervention neighbourhoods in London and 61 individuals within these neighbourhoods.
A purposive sample of parents and clinicians in the intervention arm will be invited to participate in semi-structured interviews.
A purposive sample of participants, including patients from all intervention arms, was invited to take part in an interview four to eight weeks after completion of the trial treatments.
