JMIR Publications

ABSTRACT

Background:

This multicentric retrospective observational study, conducted in outpatient routine care across 16 sites in Switzerland, investigates risk factors for non-initiation and dropout of blended therapy in psychiatric patients. It represents the second part of a series of studies, with the first paper focusing exclusively on inpatients.

Objective:

The present work focuses on outpatients and additionally provides a combined analysis including both subgroups (in- and outpatients). The objective was to identify predictors of non-initiation and dropout. As this was an observational study based on heterogeneous routine care data and without predefined primary predictor hypotheses, the analyses were conducted in an exploratory manner.

Methods:

Patients were classified into non-initiation and dropout groups based on whether they logged into the system and completed the assigned therapy modules, distinguishing those who never or only once logged in without completing modules (non-initiation group) from those who began the therapy but did not complete all modules (dropout group). Multivariable logistic regression models were conducted to identify significant predictors of non-initiation and dropout.

Results:

A key finding, consistent with the first study, is that increasing age is significantly associated with a lower risk of both non-initiation and dropout (calculation per year: non-initiation both settings: OR = 0.98 per year, 95% CI: 0.97–0.99, p = 0.002, non-initiation outpatients: OR = 0.98, 95% CI: 0.96–1.00, p = 0.045; dropout both settings: OR = 0.98, 95% CI: 0.97–1.00, p = 0.012; dropout outpatients: OR = 0.98, 95% CI: 0.96–1.00, p = 0.046). In addition, comorbid substance use disorders were associated with an increased risk of non-initiation (both settings: OR = 1.59, 95% CI: 1.03–2.45, p = 0.035; outpatients: OR = 2.01, 95% CI: 1.07–3.76, p = 0.030). Anxiety disorders were associated with a reduced risk of dropout in the combined subgroup analysis (OR = 0.57, 95% CI: 0.32–1.00, p = 0.049). Furthermore, dropout risk was significantly higher among outpatients compared to inpatients (OR = 2.24, 95% CI: 1.41–3.57, p < .001).

Conclusions:

The finding that older age is associated with higher treatment initiation and adherence aligns with existing literature suggesting better adherence among older patients. The elevated risk of non-initiation in patients with comorbid substance use disorders is consistent with prior evidence of reduced adherence in this population, potentially due to reduced illness insight, organizational difficulties, or impairments in executive functioning. The protective association of anxiety disorders with dropout replicates findings from previous work and may reflect increased treatment engagement. Finally, the higher dropout risk in outpatient settings underscores challenges in maintaining adherence where BT is most frequently implemented. Overall, these findings highlight age, comorbid substance use disorders, anxiety disorders, and treatment setting as relevant factors influencing treatment initiation and dropout in BT.