It was hypothesised that negative RA related illness cognitions are strongly related to the neuroticism trait and act as a common factor behind other self reported subjective symptoms (pain and ADL status), mood, and positive RA related illness cognitions; but are unrelated to objective indices of impairment (disease duration, C reactive protein (CRP), and joint stiffness).
To examine the relative influence of negative illness cognitions and neuroticism versus degree of impairment on subjective symptoms, positive illness cognitions, and mood in rheumatoid arthritis (RA).
Structural equation modelling analyses (LISREL) were performed on two independent samples of patients with RA consisting of 212 outpatients and 105 inpatients, respectively.
The hypotheses were largely confirmed. Firstly, negative RA cognitions were found to be dependent on neuroticism. Secondly, negative RA cognitions had a strong and dominating influence on all other self reported data. Subjective symptoms were equally well explained by negative RA cognitions as by degree of impairment. No relations were found between negative RA cognitions (or neuroticism) and degree of impairment.
The findings suggest that neuroticism, recognised as a relatively stable personality trait, strongly influences self rated symptoms and wellbeing in RA. This has important clinical implications concerning the use of standardised self rating questionnaires commonly used to assess illness status in RA and the long term effectiveness of psychological interventions and patient training courses in RA rehabilitation.