Comparison of the working alliance in blended-cognitive behavioural therapy and treatment as usual for depression in Europe: Secondary data analysis from the E-COMPARED randomised controlled trial (Preprint)

Abstract

Increasing interest has centred on the psychotherapeutic working alliance as a means of understanding clinical change in digital mental health interventions in recent years. However, little is understood about how and to what extent a digital mental health program can have an impact on the working alliance and clinical outcomes in a blended (therapist plus digital program) cognitive behavioural therapy (bCBT) intervention for depression.

To test the difference in working alliance scores between bCBT and treatment-as-usual (TAU); examine association between working alliance and depression severity scores in both arms; and test for an interaction between system usability and working alliance, on the association between the working alliance and depression scores in bCBT at 3-month assessments.

A secondary data analysis from a non-inferiority trial comparing bCBT with TAU across nine European countries was conducted. Data were collected in primary care and specialised services across nine European countries between April 2015 and December 2017. Eligible participants aged 18 years or older and diagnosed with major depressive disorder were randomized to either bCBT (n=476) or TAU (n=467). bCBT consisted of 6-20 sessions of bCBT (involving face-to-face sessions with a therapist and an internet-based program). TAU consisted of usual care for depression. The main outcomes were scores on working alliance (measured by Working Alliance Inventory-Report Form-Client (WAI-SR-C)); depressive symptoms (Patient Health Questionnaire-9 (PHQ-9)), at 3-months. Other variables included system usability scores (System Usability Scale-Client (SUS-C)) at 3-months and demographic information collected at baseline. Data from baseline and 3-month assessments were analysed using generalized linear regression models that adjusted for a set of baseline variables.

Of the 945 participants, 644 (68%) were female, and the mean age was 38.96 years (IQR=38). bCBT was associated with higher composite WAI-SR-C scores compared to TAU (unstandardised coefficients beta [95% CI]: 5.67 [4.48-6.86]). Higher WAI-SR-C composite scores were associated with a significant decrease in PHQ-9 scores in bCBT (e.g., composite scores: -0.12 [-0.17 to -0.06]) and in TAU (e.g., composite scores: -0.06 [-0.11 to -0.02]). Finally, there was a significant interaction of SUS-C and WAI-SR-C, on an inverse association between higher WAI-SR-C scores and lower PHQ-9 scores in bCBT (b= -0.030, [95% CI: -0.05 to -0.01] P=0.005]).

To our knowledge, this is the first study to show that bCBT may enhance the client working alliance when compared to evidence-based routine care for depression. The working alliance in bCBT was also associated with clinical improvements, that appear to be enhanced by good program usability. Our findings add further weight to the view that the addition of iCBT to face-to-face CBT, can positively augment experiences of the working alliance.

France: ClinicalTrials.gov NCT02542891. Registered on 4 September 2015; Germany: German Clinical Trials Register DRKS00006866. Registered on 2 December 2014; The Netherlands: Netherlands Trials Register NTR4962. Registered on 5 January 2015; Poland: ClinicalTrials.Gov NCT02389660. Registered on 18 February 2015; Spain: ClinicalTrials.gov NCT02361684. Registered on 8 January 2015; Sweden: ClinicalTrials.gov NCT02449447. Registered on 30 March 2015; Switzerland: ClinicalTrials.gov NCT02410616. Registered on 2 April 2015; United Kingdom: ISRCTN registry, ISRCTN12388725. Registered on 20 March 2015. Denmark: ClinicalTrials.gov NCT02796573. Registered 1st June 2016.

RR2-https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-016-1511-1