Research projects

A randomised control trial of a web-based intervention to improve depression, cognitive function and adherence in people with cardiovascular disease (CVD)

Principal researchers

Prof Ian Hickie

Institution

University of Sydney

Funding

$297,100 from beyondblue – Total funding $594,200

Co-funded with

Heart Foundation

Award type

Cardiovascular Disease and Depression Strategic Research Program

Project completion year

2012

Key Findings

  •  This trial of 562 participants compared the health outcomes of people with depressive symptoms and cardiovascular disease risk factors, who used an online cognitive behavioural therapy program for depression (E-couch), with those who used an equivalent online program that delivered healthy lifestyle information about nutrition, physical activity, blood pressure and cholesterol and heart health.
  • The participants who used E-couch improved their depression by 40 per cent, compared to those just given healthy lifestyle information. Participants were also 40 per cent less likely to be depressed after using the program.
  • Those who used E-couch also reported better adherence to medical treatments and some improvements in their lifestyle.
  • These research findings have a far-reaching impact, with more 8000 people using the freely available online program every month nationally. E-couch comprises 12 modules of psychoeducation, cognitive behaviour therapy, and interpersonal psychotherapy techniques that have been shown to be effective against depression in younger people without other health problems.
  • In high income countries like Australia, cardiovascular disease and depression are the two leading causes of disease burden. Depression is more common in people who have cardiovascular disease, and can prevent people from regaining their health. Evidence suggests that people with both depression and cardiovascular disease have poorer health outcomes because they are less likely to follow medical treatments and exercise less. This study shows that for people with mild to moderate depression and physical health problems, online interventions targeting mood problems are more effective at improving psychological health and some aspects of physical health than health and lifestyle advice alone.

Methodology

The Cardiovascular Risk E-couch Depression Outcome (CREDO) research trial was an internet based, double-blind, parallel group randomised controlled trial comparing the effectiveness of internet cognitive behavioural therapy (E-couch) with an online attention control (HealthWatch). The web based interventions and associated assessments were developed in collaboration with the Centre for Mental Health Research, Australian National University and CogState Ltd, between 2009 and 2010. Participants were recruited through the 45 and Up Study, a large-scale longitudinal  population based cohort study comprising over 260,000 men and women aged 45 years and over in NSW.

Recruitment to the trial commenced in July 2010 and continued through to January 2011. Of 7086 invitations to potential participants, 1862 (26 per cent) provided their consent and proceeded to eligibility screening. Those consenting were more likely to be female, speak English at home, have a higher education and a prior doctor’s diagnosis of depression. Only 696 (37 per cent) of the 1862 consenting participants met trial inclusion criteria. Of those that met criteria, 116 (17 per cent) failed to complete initial screening in its entirety and a further 18 (2.5 per cent) withdrew their consent before trial commencement. This left 562 participants with both depressive symptoms and cardiovascular disease (CVD) risk factors who were randomised to receive either Ecouch or the attention-control condition, HealthWatch. All randomised participants completed a comprehensive baseline assessment via the CREDO website, and underwent the 12-week intervention. Upon completion of the 12-week intervention period, all participants were invited to complete a follow-up assessment. Participants were also invited to complete further follow-up assessments at six months and at 12-months, in order to determine if any intervention effects were sustained over time. The final sample (N=562) was in excess of the pre-specified sample size that was calculated to detect a minimum difference between groups in depressive symptom scores. As such, the trial was established with sufficient power to enable detection of clinically significant changes in the primary outcome; a reduction in depressive symptoms.

Results

The primary pre-specified outcome for the CREDO clinical trial was the change in depressive symptoms from baseline to post-intervention (12-weeks). This was measured using the PHQ-9; a nine-item self report assessment of depressive symptoms, providing a summary score ranging from 0 to 27. The PHQ-9 is a reliable and valid measure, widely used in previous community studies of people with depression and is sensitive to change in clinical status. Following the intervention period, participants in both study arms showed improvement in their depressive symptoms by, on average 3.66 (95% CI: 3.05-4.27) with E-couch and 2.60 points (95%CI 2.05-3.16) with HealthWatch. The decline observed in the E-couch arm was significantly greater compared to HealthWatch (1.06; 95%CI: 0.23-1.89; p=.012). These results demonstrate that an internet-delivered cognitive behavioural therapy program (E-couch) can improve mood in people with mild to moderate depression and physical health problems, and more so than internet delivered health and lifestyle advice. The majority of trial participants had existing, treated cardiovascular disease, and more than half another chronic physical problem. While these effects are modest in size, they demonstrate that internet delivered cognitive behavioural therapy has the potential to be applied as a low intensity psychosocial intervention to large numbers of people being treated for cardiovascular disease, at minimal cost.

These findings were published in PLoS One (Glozier et al,. Internet-delivered cognitive behavioural therapy for adults with mild to moderate depression and high cardiovascular disease risks: a randomised attention-controlled trial. PLoS One, 2013; 8(3):e59139). 

The secondary pre-specified outcome for the CREDO trial was a change in cognitive function at 12-month follow-up. This analysis is currently underway with results expected to be available in the near future.

Our other secondary pre-specified outcome for the CREDO clinical trial was the change in adherence to CVD treatment and lifestyle advice, as measured using the “specific” component score of the Medical Outcomes Study (MOS) Measures of Patient Adherence Scale. This measure (score 0-100) is constructed from 15 questions assessing adherence to treatment and healthy behaviour recommendations e.g. exercise, diet and social support. The scale has been shown to be sensitive to changes in adherence and mood. Following the intervention period, participants in the E-couch arm reported adherence scores 2.16 points (95% CI: 0.33-3.99) higher compared to those in the HealthWatch arm. This improvement in adherence to treatment among E-couch participants was significant (t=2.32; p=.021) and demonstrates that internet-delivered cognitive behavioural therapy can improve self reported adherence in people with mild to moderate depression and cardiovascular risk factors, and more so that internet delivered health and lifestyle advice.

This is the first known trial to provide evidence that an intervention that reduces depression has additional adherence benefits. Of note, those in the attention control condition (HealthWatch) reported no change in adherence to health and lifestyle advice such as exercising regularly, cutting down on salt, and following medication recommendations despite the control arm focussing specifically on providing information on the health impact of modifying such behaviours. This suggests that the cognitive behavioural techniques and processes provide much greater impact that just health information provision alone.