Ethnocultural differences in symptom change, engagement, and adherence in internet-delivered cognitive behavioral therapy: A secondary analysis of a healthcare-embedded longitudinal study.

BACKGROUND

Internet-delivered cognitive behavioral therapy (iCBT) is a scalable approach to address the mental health treatment gap. Its effectiveness for People of Diverse Ethnocultural Backgrounds (PDEGs) remains uncertain due to persistent underrepresentation in research and routine care.

OBJECTIVE

This secondary analysis examined ethnocultural differences in symptom change, engagement, and adherence in a healthcare-embedded iCBT program, and whether engagement or adherence mediated ethnocultural differences in treatment outcomes.

METHODS

Data from 2604 adults receiving guided iCBT for depression and anxiety through the Online Therapy Unit in Saskatchewan, Canada (February 2020-December 2021) were analyzed. Participants were categorized as White (n = 2281) or PDEGs (n = 323; multiple ethnocultural subgroups). Engagement metrics included logins, therapist messages, and phone contacts. Adherence metrics included lessons completed, program completion (≥4 lessons), and weekly questionnaire submission. Depression and anxiety were assessed using the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7. Regression and mixed-effects models compared outcomes across groups, controlling for age, dataset, and baseline symptoms. Exploratory mediation analyses were conducted.

RESULTS

Both groups showed significant reductions in depression and anxiety, with no differences in symptom improvement. Engagement was comparable. However, PDEGs were less likely to complete the program. Mediation analyses did not indicate engagement or adherence explained outcome differences.

CONCLUSIONS

Our findings did not indicate differences in symptom improvement or engagement between White participants and PDEGs, although aggregation due to small subgroup sizes may have obscured subgroup-specific differences. Modest adherence differences and PDEG underrepresentation highlight the need for further research to understand barriers to program completion and equitable access to iCBT.