ARTICLE
OPEN
A pragmatic randomized waitlist-controlled effectiveness and
cost-effectiveness trial of digital interventions for depression
and anxiety
Derek Richards
1,2
✉
, Angel Enrique
1,2
, Nora Eilert
1,2
, Matthew Franklin
3
, Jorge Palacios
1,2
, Daniel Duffy
1,2
, Caroline Earley
1,2
,
Judith Chapman
4
, Grace Jell
4
, Sarah Sollesse
4
and Ladislav Timulak
1
Utilization of internet-delivered cognitive behavioural therapy (iCBT) for treating depression and anxiety disorders in stepped-care
models, such as the UK's Improving Access to Psychological Therapies (IAPT), is a potential solution for addressing the treatment
gap in mental health. We investigated the effectiveness and cost-effectiveness of iCBT when fully integrated within IAPT stepped-
care settings. We conducted an 8-week pragmatic randomized controlled trial with a 2:1 (iCBT intervention: waiting-list) allocation,
for participants referred to an IAPT Step 2 service with depression and anxiety symptoms (Trial registration: ISRCTN91967124). The
primary outcomes measures were PHQ-9 (depressive symptoms) and GAD-7 (anxiety symptoms) and WSAS (functional impairment)
as a secondary outcome. The cost-effectiveness analysis was based on EQ-5D-5L (preference-based health status) to elicit the
quality-adjust life year (QALY) and a modified-Client Service Receipt Inventory (care resource-use). Diagnostic interviews were
administered at baseline and 3 months. Three-hundred and sixty-one participants were randomized (iCBT, 241; waiting-list, 120).
Intention-to-treat analyses showed significant interaction effects for the PHQ-9 (b = −2.75, 95% CI −4.00, −1.50) and GAD-7
(b = −2.79, 95% CI −4.00, −1.58) in favour of iCBT at 8-week and further improvements observed up to 12-months. Over 8-weeks
the probability of cost-effectiveness was 46.6% if decision makers are willing to pay £30,000 per QALY, increasing to 91.2% when
the control-arm's outcomes and costs were extrapolated over 12-months. Results indicate that iCBT for depression and anxiety is
effective and potentially cost-effective in the long-term within IAPT. Upscaling the use of iCBT as part of stepped care could help to
enhance IAPT outcomes. The pragmatic trial design supports the ecological validity of the findings.
npj Digital Medicine (2020) 3:85 ; https://doi.org/10.1038/s41746-020-0293-8
INTRODUCTION
Stepped-care models have been proposed as a potential solution
1
to bridge the substantial gap between the prevalence of common
mental health disorders, including depression and anxiety, and
the access rates for evidence-based treatments
2,3
. Stepped-care
seeks to up-scale treatment initiatives by matching treatment
intensity and duration to clients' presenting needs, thereby
optimizing outcomes and service capacity utilization. Investing
in upscaling initiatives for mental health treatments is projected to
produce large returns at a benefit-to-cost ratio of 3.3–5.7 to 1
when accounting for economic benefits and the value of health
returns
4
. The Improving Access to Psychological Therapies (IAPT)
programme in the UK is one of the first examples of a mental
health stepped-care model implemented nationwide
5
.
IAPT services offer evidence-based treatments to individuals
experiencing depression and/or anxiety, providing low-intensity
interventions alongside traditional treatments (e.g. face-to-face
therapy)
5
. Specifically, at Step 2, low-intensity interventions are
offered to patients presenting with mild to moderate depression
and anxiety symptoms, while those with more severe or complex
presentations of depression and anxiety are assigned to step 3
high-intensity treatments. Low-intensity interventions include
empirically established treatments like guided bibliotherapy and
internet-delivered cognitive behavioural therapy (iCBT). Similar
multicomponent models of care exist in other countries, such as
the collaborative care models in the USA
6
. A key aspect of IAPT is
routine outcome monitoring, which is used to improve individual
clinical outcomes by aiding ongoing treatment decisions, but also
to establish publicly available service-level clinical performance
reports
7
. In the period 2018–19, IAPT received 1.6 million new
referrals, of which 1.09 million were seen at least once for
assessment and guidance and 582,556 received a course of
therapy (defined as two or more sessions)
8
.
Political and policy initiatives that helped establish IAPT
promised significant economic benefits, claiming that making
evidence-based psychological treatments available would have no
net cost to the Treasury
9
, yet envisioned economical returns from
IAPT remain debated
10
. Internet-delivered interventions may be
one way to improve IAPT outcomes in a cost-effective way
11
.
However, currently iCBT accounts for only 7% of treatments
completed within IAPT
8
. Clark et al. found that amongst services
that achieve lower treatment rates, engaging more users in
treatment could improve recovery and reliable improvement by
33% and 90%, respectively
7
, highlighting the potential for
increased use of iCBT within IAPT to help achieve this aim.
Generally, iCBT for depression and anxiety has been found to
significantly reduce symptoms and produce medium to large
effect sizes at post-treatment, with a maintenance of effects at
follow-up
12
. As a result, iCBT has established itself as a viable
mode of treatment for depression and anxiety. Still, most research
has explored iCBT's efficacy under more controlled settings, with
effectiveness trials in routine care finding mixed outcomes
12,13
.
1
University of Dublin, Trinity College, School of Psychology, E-mental Health Research Group, Dublin, Ireland.
2
Clinical Research & Innovation, SilverCloud Health, Dublin, Ireland.
3
HEDS, ScHARR, University of Sheffield, Sheffield, England.
4
Berkshire Healthcare NHS Foundation Trust, London, Berkshire, England.
✉
email: derek.richards@tcd.ie
www.nature.com/npjdigitalmed
Scripps Research Translational Institute
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