Behaviour Change Intervention (BCI) scenarios consist of:
- the target behaviour
- the intervention itself (including its content and delivery)
- factors that influence the impact of the intervention on the behaviour which are ‘engagement’ with the intervention and the ‘context’ (the setting for the intervention, the target population, and other events that may be taking place at that time)
- mechanisms of action through which interventions have their effects on behaviour.
If we have full information about all of these components of the BCI scenario and we have an accurate causal model of how they interact causally, we should be able to predict what the outcome will be in terms of the target behaviour (what we refer to as the outcome value).
For example, if the behaviour is ‘smoking cessation for 12 months’, the population is ‘smokers making a quit attempt aged over 18 years in Warsaw, Poland and willing to take a medicine to help them stop smoking’, the intervention is ‘use of cytisine taken orally as prescribed for 25 days together with brief behavioural support delivered face to face, all provided free of charge with follow-up at 1, 4, and 26 weeks’, 80% take the medicine as prescribed, and the setting is ‘an outpatient hospital facility’, we may observe an outcome value of 8.3%.
Interventions have their effects on behaviour through one or more mechanisms of action. And these are included in the BCIO scenario to support the building of models from which the effectiveness of interventions can be predicted.
