Is avoidant coping independent of disease status and stable over time in patients with ankylosing spondylitis?

OBJECTIVE: To determine whether avoidant coping in ankylosing spondylitis (AS) is independent of disease status and whether it is stable over time.
METHODS: 658 patients with AS completed a postal questionnaire on health status, including pain and stiffness (BASDAI), physical function (BASFI), and coping (CORS). In CORS, "decreasing activities to cope with pain" and "pacing to cope with limitations" reflect avoidant behavioural coping. Ninety patients continued in a longitudinal study and 70 completed the CORS after four years. The adjusted contribution of age, sex, disease duration, educational level, pain (BASDAI), and physical function (BASFI) to the two avoidant coping strategies at first assessment was determined by multiple linear regression. Agreement between coping at first assessment and four years later was determined by intraclass correlation, and the correlation between change in coping and change in disease status over time by Pearson's correlation.
RESULTS: At first assessment, worse physical function (BASFI) and more pain (BASDAI) were associated with "decreasing activities to cope with pain". Worse physical function, but not pain, was associated with "pacing to cope with limitations". The contribution of physical function or pain to the total explained variance in each of the coping strategies was small. Disease duration was not a determinant of avoidant coping, but greater age was associated with "pacing to cope with limitations". Change in avoidant coping strategies over time could not be explained by change in function or pain.
CONCLUSIONS: In AS, avoidant coping at a particular time is largely independent of disease duration or status. Variability in avoidant coping over a limited period of four years cannot be explained by change in disease status.