Acceptance in the Context of Spinal Cord Injury: A multi-method exploration of the conceptualization of acceptance and its associations with mental health and quality of life

People who sustain a spinal cord injury (SCI) are often faced with a range of health complications such as paralysis, loss of sensation, breathing trouble, bowel and bladder dysfunction, chronic pain, and more. This is often accompanied by negative psychological adjustment outcomes with an estimated rate of depression of 22% and significantly lower quality of life (QoL) compared to the general population. However, many people with SCI conversely show favorable trajectories of psychological adjustment over time. There are many biomedical, psychological, and sociocultural factors involved in adjustment processes, including acceptance of the injury, which has been shown across many studies to play an important role. However, there are a range of practical, methodological, and conceptual limitations and knowledge gaps within the research field.

First, acceptance is often subsumed into the broader coping construct leading research findings on the specific associations between acceptance and psychological adjustment outcomes to be scattered. It is therefore difficult and very time-consuming for researchers and rehabilitation professionals to get a comprehensive and reliable overview of the research field. A systematic review of the literature is needed to provide such an overview. This is mostly a practical limitation, but there are also important methodological and conceptual limitations. Acceptance has historically been described and defined in a variety of ways that are similar in some respects but distinct in others. In most empirical research, the term acceptance is used as a general construct with no explicit reference to the specific conceptual underpinnings. There is therefore a crucial need for research into the potential multidimensional nature of acceptance processes, and how different facets of accepts might be differentially associated with psychological adjustment outcomes. Finally, acceptance is not just a psychological construct. It is a word used in daily language and, to some, it can mean giving up or settling for less. While this is not what is meant in the psychological literature, such an understanding of acceptance could potentially skew results that are based on questionnaire data. It is therefore important to determine whether the scales that are used to measure acceptance are in fact measuring what they are intended to measure.

This PhD thesis includes four papers that use different methods to address these practical, methodological, and conceptual knowledge gaps. The aims of these four papers were to: 1) systematically identify, critically appraise, and synthesize research findings on the associations between acceptance of SCI, QoL, and mental health outcomes, 2) develop and validate a multidimensional conceptualization of acceptance, 3) investigate how different facets of acceptance are associated with QoL after statistically adjusting for psychological distress, and 4) to validate the Danish version of the Spinal Cord Lesion-related Coping Strategies Questionnaire in a mixed-methods approach.

In paper 1, five online databases were systematically searched for studies on the associations between acceptance, QoL, and mental health outcomes. A total of 41 studies met our eligibility criteria and were included. All studies were assessed for risk-of-bias and data were extracted and synthesized. Overall, acceptance was strongly and consistently associated with greater global and psychological QoL, life satisfaction, sense of well-being as well as lower depression and anxiety. Inconsistent evidence was found for social QoL and PTSD. Further, acceptance was associated with these adjustment outcomes over and above what was explained by potential confounding factors, and it was a significant predictor of psychological adjustment in longitudinal studies up to two years post-injury.

In paper 2, a multidimensional conceptualization of acceptance, based on different theoretical perspectives, was developed. This conceptualization was validated in a split-sample exploratory and confirmatory factor analysis approach (N = 431). The results showed good model fit adding empirical evidence for a model of acceptance with four facets that were labeled ‘accepting reality’ (i.e., an acknowledgement of the reality of a situation), ‘valuechange’ (i.e., reevaluation of life values and interests), ‘letting go of control’ (i.e., being with whatever is present rather than trying to control or avoid distressing inner experiences), and ‘behavioral engagement’ (i.e., engaging in personally valuable life activities even in the presence of distressing inner experiences).

In paper 3, a series of hierarchical multiple linear regression analyses were performed (N = 376) to determine how the four different facets of acceptance were associated with QoL. The results showed that acceptance uniquely explained between 6% and 14% of the variance in QoL after sociodemographic and injury-related variables, depression, and anxiety were controlled for. In terms of specific predictors, ‘value-change’ and ‘behavioral engagement’ were found the be the strongest and only consistent facets to contribute significantly to the models. Collectively, these findings indicated that ‘value-change’ and ‘behavioral engagement’ adds something unique to the experience of QoL rather than merely being associated with lower depression and anxiety.

In paper 4, the SCL-CSQ was translated into Danish and validated using a mixedmethods approach. The quantitative results (N = 107) showed that the acceptance subscale had acceptable internal consistency and criterion validity, while the data from a three-step test interview approach (N = 11) showed that three out of four acceptance items were interpreted congruently by most respondents. One item had 45% congruent responses and was therefore deemed problematic. The other subscales of the SCL-CSQ (i.e., fighting spirit and social reliance) were also validated. The results for these showed that fighting spirit had no concerning issues, while the social reliance subscale showed inadequate internal consistency and criterion validity as well as having two out of three items with 9% and 27% congruent responses.

In the discussion of this thesis, the findings of the four papers are discussed in relation to existing research such as how the multidimensional conceptualization of acceptance could be understood in relation to the transtheoretical model of behavior change; how acceptance, QoL, and psychological distress are interconnected; the potential of increasing acceptance through interventions such as Acceptance and Commitment Therapy; and patient perceptions of acceptance. Limitations and potential biases are also discussed, including the lack of metaanalysis; potential evidence selection bias and publication bias; the non-exhaustiveness of the multidimensional conceptualization; the representativeness of the study samples and generalizability of findings; and cross-cultural differences. Furthermore, the overall clinical and research implications are discussed, including how the current thesis underlines acceptance as a psychological resource; how it provides a framework for understanding the nuances of acceptance; how it emphasizes the ‘value-change’ and ‘behavioral engagement’ aspects of acceptance in clinical rehabilitation; and how it highlights the importance of determining validity based on response processes. Finally, we broaden the perspective and discuss where to go from here, including the value of developing a new acceptance scale; investigating the efficacy an acceptance-based intervention; potential interactions between acceptance and hope; conceptual overlaps with other constructs; and viewing acceptance in a dyadic perspective.