Compassion-Focused Therapy for Chronic Pain

Pain Management Programmes help people to manage their pain and improve quality of life, and this research will look into the processes by which this happens. This study will look at two psychological concepts: 'self-compassion' (kindness to self) and 'psychological flexibility' (willingness to tolerate difficult experiences in order to meet meaningful goals). These concepts help in understanding how people think about themselves in the context of pain.

Principle Research Question: Do self-compassion and psychological flexibility mediate change (anxiety/depression/well-being) in a Compassion-Focused Therapy group for adults with chronic pain?

Primary Outcome Measure: Strength of mediation effects

Sample Size:

[Reference 1] propose guidelines for recommended sample sizes in order to detect mediation effects with .8 power. These guidelines are informed by existing literature in the field. There is less robust research on self-compassion and chronic pain, therefore, this calculation is based on research in psychological flexibility and chronic pain.

[Reference 2] conducted correlational analyses on the processes of psychological flexibility following a group intervention based on ACT. These processes included acceptance of pain, mindfulness, psychological acceptance and values-based action (r values between 0.33 and 0.55). These positive correlations indicate that the group intervention was related to higher levels of psychological flexibility.

[Reference 3]'s review identified several studies that reported correlational effect sizes between acceptance, and depression/anxiety/daily functioning related to chronic pain (r = -0.58/-0.66/0.47 respectively). These negative correlations illustrate that higher levels of psychological flexibility were related to better outcomes.

Based on these correlational effect sizes, guidelines in [Reference 1] suggest that a sample size of 53-71 is required.

Analysis:

The analysis will focus on the proposed mediating factors (self-compassion and psychological flexibility) and how they explain the outcome of the CFT-incorporated group intervention. In order to study the processes of change, this study will measure change in mediators and outcomes over the course of the group.

In a mediation model, the effect of the independent variable (IV; CFT group) on a dependent variable (DV; outcome/change in symptoms) is conveyed through a third mediating variable. In order to be a mediator, a variable must change during the intervention, be associated with the intervention, and have an impact on the outcome.

In this study, it is hypothesised that self-compassion and/or psychological flexibility are the mediating variables that explain the influence of the group intervention on eventual outcome, i.e. the overall change in symptoms at the end of the group. Linear regression and nonparametric bias-corrected bootstrap, which corrects for skew in the data, will be applied to the data using SPSS, using the PROCESS macro. An effect of mediation will be indicated if the confidence interval does not contain zero.

Missing data will be handled using either the maximum likelihood or multiple imputation method, as recommended in literature.

Please note this study is only recruiting people who have been referred and accepted onto NHS Lothian's Pain Management Programme (part of the Lothian Pain Service at the Astley Ainslie Hospital).

Inclusion criteria

• Fluency of English sufficient for participation in the group and completion of questionnaires
• Aged 18+ (no upper age limit)
• Ability to provide informed consent (as defined by the Five Statutory Principles of the Mental Capacity Act, Code of Practice, 2007)

Exclusion criteria

• Active substance misuse
• Active suicidality
• Terminal illness
• Inability to provide informed consent