Disease severity and psychological status in ankylosing spondylitis

Abstract

The findings of this study provide an original contribution to knowledge in ankylosing spondylitis (AS) and have important implications for eiThancing clinical practice. The results demonstrate the existence and significance of associations between disease and psychological status in AS, and also demonstrate the value of using longitudinal, repeated measures approach to study this long-term condition. This study is also the first to demonstrate the value of using a mixed methods approach to investigate this issue in AS.
Although existing literature on prospective longitudinal cohort studies in AS is very limited (other than for studies which involve clinical trials of medications and other interventions), this project demonstrates the feasibility of sustaining such a study over an 18-month period and of recruiting large numbers of participants to both the quantitative and qualitative phases.
The results are based upon a hospital-ascertained cohort of 89 adults. Both the quantitative and qualitative phases produced important new findings:
1. In this cohort, mean BASMI, BASFI and BASDAI scores remained consistent throughout the 18-month period. People with BASDAI scores higher than 4 at the beginning of the study continued to score higher than 4 throughout.
2. BASMI, BASFI and BASDAI scores correlated significantly with anxiety, depression and internality scores, but not with levels of belief in chance or powerful others, throughout the study. This demonstrates that AS disease status is closely linked to some, but not all, psychological measures.
3. There was no effect of co-existent psoriasis or iritis on either disease or psychological status, but BASMI and BASFI (but not BASDAI) scores were significantly related to age.
4. Factors which appear to influence the associations between disease and psychological status are highly complex, often differing between individuals, and usually determined by other co-morbidities and life circumstances besides AS.

These results suggest that the major implication for clinical practice would be the development of a more comprehensive and integrated assessment framework for AS set within the context of a biopsychosocial model. Envisaged would be a major programme of work to critically assess and validate potential components of such a framework with the aim of determining efficacy, feasibility and acceptability of such an approach.