Prevalence and factors associated with disturbed sleep in patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis: a systematic review

This review explores the prevalence and factors associated with disturbed sleep for patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis in order to clarify consistent findings in this otherwise disparate research field. The association of physical, demographic and psychological factors correlating with poor sleep was explored, and the effectiveness of interventions assessed. Ten electronic databases were searched: AMED, CINAHL, Embase, Medline, PsycINFO, PubMed, Scopus, Web of Science, OpenGrey and BASE. Following application of inclusion and exclusion criteria, 29 articles were critically assessed on the basis of methodology, experimental design, ethics and quality of sleep data, leading to the selection of 15 studies for final review. Poor sleep was reported in 35–90% of patients with axial spondyloarthritis and is more prevalent within this clinical population compared to healthy control subjects. Disturbed sleep is an important aspect of disease for patients and reflects the severity of disease activity, pain, fatigue and functional disability. However, the direction of this relationship is undetermined. Associations with age, gender, years spent in education, quality of life and depression have also been demonstrated. Anti-TNF medication is effective in reducing poor sleep, and exercise has also produced beneficial results. Future research into poor sleep should take account of its multifactorial nature. There is also a current lack of research investigating non-pharmacological interventions or combination therapies. A standardised, validated measurement of poor sleep, appropriate for regular patient screening, would be a useful first step for future research.