Efficacy of a Blended Low-Intensity Internet-Delivered Psychological Program in Patients With Multimorbidity in Primary Care: Randomized Controlled Trial
Authors: Monreal-Bartolomé Alicia , Castro Adoración , Pérez-Ara M Ángeles , Gili Margalida , Mayoral Fermín , Hurtado María Magdalena , Varela Moreno Esperanza , Botella Cristina , García-Palacios Azucena , Baños Rosa M , López-Del-Hoyo Yolanda , García-Campayo Javier , Montero-Marin Jesus 
Published: October 2024

Background
Multimorbidity is a highly prevalent phenomenon whose presence causes a profound physical, psychological, and economic impact. It hinders help seeking, diagnosis, quality of care, and adherence to treatment, and it poses a significant dilemma for present-day health care systems.

Objective
This study aimed to assess the effectiveness of improved treatment as usual (iTAU) combined with a blended low-intensity psychological intervention delivered using information and communication technologies for the treatment of multimorbidity (depression and type 2 diabetes or low back pain) in primary care settings.

Methods
A 2-armed, parallel-group, superiority randomized controlled trial was designed for this study. Participants diagnosed with depression and either type 2 diabetes or low back pain (n=183) were randomized to “intervention + iTAU” (combining a face-to-face intervention with a supporting web-based program) or “iTAU” alone. The main outcome consisted of a standardized composite score to consider (1) severity of depressive symptoms and (2a) diabetes control or (2b) pain intensity and physical disability 3 months after the end of treatment as the primary end point. Differences between the groups were estimated using mixed effects linear regression models, and mediation evaluations were conducted using path analyses to evaluate the potential mechanistic role of positive and negative affectivity and openness to the future.

Results
At 3-month follow-up, the intervention + iTAU group (vs iTAU) exhibited greater reductions in composite multimorbidity score (B=–0.34, 95% CI –0.64 to –0.04; Hedges g=0.39) as well as in depression and negative affect and improvements in perceived health, positive affect, and openness to the future. Similar positive effects were observed after the intervention, including improvements in physical disability. No significant differences were found in glycosylated hemoglobin, pain intensity, or disability at 3-month follow-up (P=.60; P=.79; and P=.43, respectively). Path analyses revealed that the intervention had a significant impact on the primary outcome, mediated by both positive and negative affect (positive affect: indirect effect=–0.15, bootstrapped 95% CI –0.28 to –0.03; negative affect: indirect effect=–0.14, bootstrapped 95% CI –0.28 to –0.02).

Conclusions
This study supports the efficacy of a low-intensity psychological intervention applied in a blended format on multimorbidity in primary care. It justifies the exploration of the conceptualization of depression in type 2 diabetes as well as the analysis of the implementation of such interventions in routine clinical practice.

Trial Registration
ClinicalTrials.gov NCT03426709; https://clinicaltrials.gov/study/NCT03426709

International Registered Report Identifier (IRRID)
RR2-10.1186/S12888-019-2037-3