Initial Validation of the Self Experiences Questionnaire-2 in People with Chronic Pain

People with chronic pain often experience a serious challenge to their identity and sense of self. In a recent BBC survey (BBC, 2022), one participant says chronic pain left her grieving for “the person she was”, and she says “I feel I’ve lost every part of my life- I’ve lost me.” Indeed, individuals’ experience of chronic pain and its burdens can lead to considerable changes in their activities and roles. Along with these changes, people with chronic pain struggle to hold onto the “real me” and suffer a “loss of identity” (Toye et al., 2013). At the same time, they experience an intrusion of a “new self” that is considerably diminished in comparison with their “old self,” regarding emotional, social, and family functioning, and satisfaction with life (Morea et al., 2008; Rodham et al., 2010).

Acceptance and Commitment Therapy (ACT) specifically includes a process related to a sense of self, called “self-as-context (SAC)”. ACT is based on a model called the Psychological Flexibility (PF) model, which includes six processes: acceptance, defusion, present-moment awareness, self-as-context, values, and committed action (Hayes et al., 2011). SAC entails the experience of an enduring sense of self that is bigger than and contains one’s thoughts, feelings, and sensations. It is like a perspective or point of view whereby one can observe these experiences rather than identifying with them (Yu & McCracken, 2016).

ACT has been widely applied in chronic pain and is beneficial for improving a range of outcomes (Hughes et al., 2017; McCracken et al., 2022). Accumulating evidence also supports the role of SAC in relation to functioning and wellbeing (Godbee & Kangas, 2020). In people with chronic pain, improvement in SAC has also been observed to be associated with improvement in functioning (Yu et al., 2017b, 2021).

A measure of SAC called the Self Experiences Questionnaires (SEQ) was initially developed in people with mixed chronic pain conditions (Yu et al., 2016), and further developed in people with fibromyalgia (Yu et al., 2017a, b). The SEQ comprises 15 items with two factors: one reflecting a sense of self separated/distinct from one’s s thoughts and feelings, namely self-as-distinction (SAD), and one reflecting a sense of self as an observer of one’s thoughts and feelings, namely self-as-observer (SAO). A shorter version of the SEQ, which maintains the two-factor structure and includes eight items, was also validated in people with mixed chronic pain conditions (Yu et al., 2021). These measures of SAC have been applied in treatment outcome studies in people with chronic pain, where significant and clinically meaningfully changes in SAC from baseline to post-treatment were observed, and these changes in SAC were associated with changes in treatment outcomes, including pain interference, daily functioning and mood (Yu et al., 2017a, b, 2021).

A briefer measure of the SAC with fewer than eight items is needed and could facilitate intensive and comprehensive assessment. First of all, individuals’ responses to psychological interventions are often dynamic, non-linear, and highly individual (Hofmann et al., 2020). Intensive assessment of PF processes, including SAC, is required to gather data that is sensitive to situational and temporal variation, where such intra- and inter-individual variability can be revealed. Secondly, comprehensive assessment of all PF processes is needed to fully understand the mechanisms of associated treatments, such as ACT, and to inform the refinement of the theoretical model. However, these efforts would result in significant assessment burden on patients or participants, and one way to reduce the assessment burden would be to develop briefer version of existing reliable and valid measures.

The aim of the current study was to establish a two-item version of the SEQ, the SEQ-2. A very brief version of the SEQ would make it feasible to assess SAC repeatedly and intensively during the treatment in order to produce fine-grained information about the change trajectory of the process in relation to outcomes, which in turn can inform personalised treatment delivery, and the development of more targeted treatments. Specifically, this study includes three objectives: (1) To identify the most robust two items of the SEQ-8, one from each factor; (2) To examine the performance of the two-item version of the measure in assessing SAC; (3) To examine the construct validity and incremental validity of the SEQ-2.

The aim of the study was to establish a two-item version of the SEQ. The newly validated SEQ-2 demonstrated acceptable reliability and appeared to perform well in assessing SAC, as evidenced by its association with the SEQ-8. The construct validity of the SEQ-2 was supported by its associations with other PF processes and measures of functioning, albeit to a slightly reduced degree compared with the SEQ-8. The incremental validity of the SEQ-2 was demonstrated by its associations with measures of functioning, which were comparable to those for the SEQ-8.

The results from this study are generally in line with findings from previous studies, where SAC was examined in people with chronic pain (Yu et al., 2016, 2017a, b, 2021). Intriguingly, SAC appeared to consistently demonstrate relatively strong correlations with committed action, in these studies. That is, people who demonstrate high level of SAC appeared to demonstrate more value-guided actions. SAC entails a sense of self that is not identified with self-concepts and self-evaluations. From the perspective of Contextual Behavioural Science (CBS), people with low level of SAC would overly identify with their self-concepts and self-evaluations, which are often negative and diminished as a result of their living experience of chronic pain. These in turn would lead to avoidant behaviour, as opposed to value-guided actions (McHugh, 2015). The negative association between SAC and committed action appears to support the role of SAC as theorized in the contextual behavioural approach to the self.

SAC also consistently demonstrated stronger association with depressive mood, compared with other measures of functioning such as pain-related interference and work and social functioning (Yu et al., 2017a, b; Yu et al., 2021). People who overly identify with their own thoughts and feelings, appear to report higher level of depressive mood. Similar patterns have also been observed in the relationship between rumination and patient outcomes, where rumination was found to predict depression, but not social functioning in people with chronic pain (McCracken et al., 2014). Taken together, “being enmeshed” in one’s thoughts and feelings appears to have a particular effect on mood.

From the CBS point of view, the core experiences of depression, such as low mood and sadness, are in many circumstances normal and adaptive, emotional responses, that can lead to chronic and maladaptive depression through experiential avoidance (Kanter et al., 2008). Indeed, it was observed, in people with chronic pain, that rumination indirectly exerted its influence on depression through pain acceptance (McCracken et al., 2014), a process reflecting the willingness to engage with undesirable thoughts and feelings, as opposed to avoidance. Perhaps treatment methods targeting acceptance, combined with techniques designed to improve SAC, can be particularly helpful for people with high level of depressive mood.

It is noted that the unique variance in these measures of pain disability and work and social functioning explained by the SEQ were limited. In the regression models, we took a statistically conservative approach to force enter pain duration, pain intensity, and pain location in the models, before the SEQ, which statistically disadvantaged the SEQ scores. At the same time, SAC is not a process that emerges from ordinary language environment. Training is often needed to foster such a perspective. For instance, in a previous longitudinal validation study of the SEQ (Yu et al., 2017a, b), the SEQ generally performed better with post-treatment data, where participants had received training in SAC. Furthermore, the correlations between SAC and measures of functioning at baseline were much smaller, compared with correlations between the changes in SAC and measures of functioning at post-treatment. Longitudinal studies that include SAC training are needed to further validate the measure. Nevertheless, this finding appears in line with what has been observed in previous studies (Yu et al., 2016, 2017a, b, 2021), and the unique variances explained by the SEQ-2 in the measures of functioning were comparable to those explained by the SEQ-8, indicating that the performance of the SEQ-2 in predicting functioning is comparable to that of the SEQ-8 in this sample.

The association between SAC and depressive mood appeared stronger than those observed in previous studies in people with chronic pain (Yu et al., 2017a, b, 2021). The data for this study was collected during the COVID-19 pandemic, when an elevated level of depression was observed among people with chronic pain. In addition, prolonged quarantines were widely enforced to control the spread of the virus. Such a restricted social environment could lead to reduced source of reinforcement for adaptive behaviours, such as engaging with meaningful activities while experiencing pain (pain acceptance), which could potentially mitigate the effect of SAC on mood. On a related note, the context of the pandemic may also have implications for the sample. For instance, the employment status of the participants might have been affected by the pandemic. The pain characteristics, such as pain intensity may have been affected due to restricted pain services during the pandemic. To reduce such impact, we controlled for demographics and pain characteristics in the analyses.

Nevertheless, the two-item SEQ that emerged here appears to be a reliable and valid measure of SAC. The availability of a very brief measure of SAC can facilitate efficient and intensive assessment of the process in clinical practice and research. Such assessment can generate time and situation-sensitive information about the process, such as if any improvement occurs after the treatment is implemented, when the improvement occurs, and the stability of change over time. Such information in turn can further inform treatment development and personalized treatment delivery.

The study includes limitations. First of all, the data for this study was collected during the COVID-19 pandemic. Some contextual factors specific to the pandemic may have exerted some influence on the relationships we observed in this study. For instance, we have discussed the stronger relationship between SAC and depression observed in this study in the context of the pandemic and the implication for the sample characteristics. Second, the sample in this study is dominantly white and women. Chronic pain is generally more common in women compared to men, and women are often overly-presented in chronic pain research. For instance, in a large Canadian online survey study (N = 2423) in people with chronic pain during the pandemic, 83.5% of the participants were women (Pagé et al., 2021). The survey was distributed in English, thus participants were likely from English-speaking countries, where the majority of the populations are often whites. Nevertheless, the limited representativeness of the sample may have implications for the generalizability of the findings. Third, although acceptable, the reliability of the SEQ-2 appeared lower than that of the SEQ-8. Nevertheless, the inter-item correlation for SEQ-2 (0.63) is higher than the mean inter-item correlation for SEQ-8, 0.59 (0.40-0.83), and the item-total correlation is 0.63 for both items of the SEQ-2, while the item-total correlation for SEQ-8 is 0.56-0.83, supporting the internal consistency of the items. Next, the discriminant validity of the SEQ-2 was not examined due to the lack of data on theoretically unrelated construct. However, the clinically-relevant incremental validity of the SEQ-2 (beyond pain intensity, duration, and pain location), was examined in addition to convergent validity. Lastly, the cross-sectional design of the study limited our ability to infer any causal relations between our study variables, or to draw conclusions on the responsiveness of the newly developed measure. Longitudinal studies are warranted in this regard.

A two-item version of the SEQ emerged from this study, and appeared an acceptable measure of SAC. The availability of the measure could facilitate more efficient and intensive assessment of SAC, where high-frequency repeated administration is needed, which in turn can help testing and refining the theoretical model in research, and inform clinical practice. Further treatment studies that include a longitudinal design and training for SAC are needed to further validate the SEQ-2.