Table 1 Definitions of the five RE-AIM dimensions and the definitions in this study

Reach (therapist)

The absolute number, proportion, and representativeness of individuals who are willing to participate in a given initiative, intervention, or program.

The number, proportion and representativeness of therapists in the participating mental health organisations that offered iCBT for depression during the study.

Effectiveness (patient and therapist)

The impact of an intervention on important outcomes, including potential negative effects, quality of life, and economic outcomes.

The (positive and negative) impact of iCBT on the therapists and patients regarding perceived effectiveness, satisfaction and usability

Adoption (organisation)

The absolute number, proportion, and representativeness of settings and intervention agents (people who deliver the program) who are willing to initiate a program.

The extent to which mental health care organisations adopt iCBT and how the therapist is facilitated in this.

Implementation (therapist and organisation)

At the setting level, implementation refers to the intervention agents’ fidelity to the various elements of an intervention’s protocol, including consistency of delivery as intended and the time and cost of the intervention.

The extent to which iCBT is implemented as intended in routine practice, including implementation barriers and facilitators from the therapist’s perspective.

Maintenance (therapist and organisation)

The extent to which a program becomes institutionalized or part of standard organizational practices and policies.

The extent to which iCBT becomes a sustained part of standard practice and facilitating and hindering factors from therapists’ and organisational perspective.