2.4. Framework analysis

The programme components of each intervention were analysed using the Theoretical Domains Framework (TDF). First, information on programme design was extracted from each study using a modified TIDieR checklist. In cases where programme descriptions in the included studies were not sufficient, related articles were sought out, and if there were none, the authors of the original studies were contacted to provide more information.

Programme descriptions were carefully compared to the description of each TDF domain for evidence that they sought to address that domain. Domains that were addressed by programme content were coded with a ‘1’, whereas others received a ‘0.’ For example, the TDF defines Goals as “End states or outcomes individual wants to achieve (e.g. target setting, action planning, priorities).” If a programme encouraged participants to set priorities or goals for their health, or provided an action plan, they were scored with a ‘1’ on this domain. SMPs received a ‘1’ on the Reinforcement domain if they provided incentives or rewards to participants, consistent with the TDF definition of that domain as “Increasing probability of desired behaviour by introducing dependency between stimulus and response (e.g. incentives, rewards, punishments).”

Each included intervention received a score based on the sum of the TDF domains addressed by the programme. The frequency with which different domains of the TDF were used in programme design were also analysed by summing the number of interventions with a ‘1’ for each domain.

Interventions that resulted in multiple included studies were only included once in this analysis. Where this was the case, the results were pooled and the first author of each relevant paper was noted.