Internet-based Acceptance and Commitment Therapy for Chronic Pain

Acceptance and Commitment Therapy (ACT) delivered face-to-face is an empirically supported intervention for the management of chronic pain (CP). However, increasing demands for cost reduction in healthcare services in addition to obstacles regarding physical access to treatment, highlight the need for innovative, cost-reducing, digital self-management interventions. Poor user engagement nonetheless, is a significant challenge often faced in digital interventions, which often results in poor adherence or even non-completion in treatment. In addition, very few digital trials appear to plan for adherence a-priori, when designing an intervention. To date there are only two ACT-based digital interventions for CP demonstrating significant improvements in pain-related disability and increased functioning, yet with small to medium effect sizes and poor adherence rates. However, several limitations of the studies such as the absence of a-priori adherence planning and lack of investigation of underlying mechanisms, makes it difficult to draw clear conclusions on the effectiveness of this new treatment modality for chronic pain and warrants further research. This study seeks to: a) explore how a brief adherence-planned digital ACT-based intervention for CP management, compared to an active control group and a wait-list control group improves targeted study outcomes such as functioning and quality of life, and b) investigate which processes of change mediate the targeted study outcomes. It is hypothesized that the brief ACT-based digital intervention in comparison to the active control group and wait-list will result in increased functioning, improved quality of life and reduced pain intensity. The results of the study are expected to shed more light on the utility of planning for adherence in digital interventions and effectiveness of ACT-based digital interventions and their underlying mechanisms in the management of CP.

A growing body of evidence demonstrates that clinic-based interventions can be effectively used to treat pain-related interference in the daily life of chronic pain sufferers. Acceptance and Commitment Therapy (ACT) delivered face-to-face is an empirically supported intervention for the management of chronic pain (CP). The increasing demands for cost reduction for services in the healthcare system and obstacles regarding physical access to treatment highlight the need for innovative, cost-reducing, self-management interventions. In addition, the idea of home-based self-management support seems appealing to a significant number of sufferers of chronic conditions such as chronic pain. Digital interventions might present with feasible means to overcome many barriers such as physical access to treatment or financial obstacles while helping improve health care for persons with chronic pain in the convenience of their space and time.

A considerable number of studies have demonstrated the effectiveness of psychological digitalised interventions (the majority cognitive and behavioural based) in improving chronic pain management, reducing pain intensity, catastrophizing and improving functioning. However, support for the effectiveness of digital interventions is tempered by a plethora of evaluations that report users often fail to adhere to online interventions. Almost twice as many users appear to dropout from internet-based interventions compared to the traditional face-to-face interventions suggesting that users become disengaged and unmotivated early on in these interventions. A-priori planning for maximised user engagement and consequently adherence, using a theoretical framework such as persuasive technology, is desirable in digital interventions that aim to combat the problem of low adherence.

To date, there are only two studies that have examined the effectiveness of ACT-based digital interventions (iACT) for chronic pain management, demonstrating significant improvements in pain-related disability and increased functioning. Despite these encouraging findings, to our knowledge, no iACT study has appropriately addressed the problem of low adherence, which has resulted in low adherence and high attrition rates in both of the ACT trials. Also, none of the two studies has investigated the impact of adherence on treatment outcomes or investigated the underlying ACT mechanisms of change on treatment outcomes within a digital tested framework. Furthermore, there have been very few attempts to examine the effectiveness of brief (\< 6 sessions) interventions in the field of ACT and CP, yet none exists in the field of iACT and CP.

The present study seeks to: a) design an innovative Avatar-led digitalised brief intervention based on a culturally sensitive ACT face-to-face protocol developed in a previous project, b) recruit and offer online treatment to community-based chronic pain sufferers, c) explore how a brief iACT intervention for CP management, compared to a waitlist control group (medical treatment as usual) and an active control group (limited access to pain-related psycho-educational information) improves targeted study outcomes (e.g., functioning and quality of life etc.), d) investigate which processes of change mediate the targeted study outcomes and e) investigate the relationship between adherence to the intervention and treatment outcomes. Assessments of chronic pain users' daily functioning (primary outcome), quality of life, affective components, pain intensity (secondary outcomes), therapeutic process measures (e.g., psychological flexibility, acceptance, defusion), will be assessed before and following treatment completion, and after 3, 6 and 12 months. In addition, user satisfaction and web-metrics (number of logins/modules/activities completed, time spent online etc.) will be assessed to examine the relationship between adherence and treatment outcomes.

It is hypothesised that the brief iACT in comparison with the two control groups will result in increased functioning, improved quality of life and reduced pain intensity mediated by the mechanisms of change of psychological flexibility, acceptance and defusion. In addition, it is hypothesized that users with increased adherence will result in significantly improved treatment outcomes as compared to users with poor adherence. The results of this study are expected to revolutionize the implementation and treatment effectiveness of brief iACT interventions in the field of chronic pain management. Furthermore, the investigators attempt to contribute to the literature concerning the improvement of designing and planning for digital interventions that target improved user engagement and adherence to treatment.

Eligibility Criteria:
Inclusion Criteria:

1. Age 18 years or older
2. At least 3 months chronic pain duration,
3. At least a pain intensity score of ≥ 4 prior to the intervention (assessed by an 11 point numeric rating scale (NRS; Dworkin et al., 2005) ranging from (0) 'no pain' to (10) 'pain as bad as the participant can imagine'.
4. Users to have undergone medical assessment within one year,
5. Official medical diagnosis on the type of chronic pain that users suffer from,
6. Regular access to a computer/tablet and internet
7. Sufficient knowledge of the Greek language.

Exclusion Criteria:

1. Comorbidity with a serious medical condition other than chronic non-malignant pain (e.g., complete paraplegia or tetraplegia, heart or vascular diseases, malignant pain such as cancer etc.), which may interfere with participation. A neurologist will be consulted and candidates will be excluded if their medical condition is regarded as significantly interfering with their participation.
2. Recent episodes of active psychosis, manic episodes, substance use disorder and suicidal ideation. Assessment will take place using selected single items from mini-SCID (mini - Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders Karekla \& Panayiotou 2010). Candidates who respond positively to one or more of the assessed mini-SCID items will be excluded from further participation and will receive information over the phone with advice to seek help, along with relevant information on available services from their local community mental health services or their general practitioner.