Negative and positive illness representations of rheumatoid arthritis: a latent profile analysis.

This study extends previous work to consider whether individuals with rheumatoid arthritis (RA) can be categorised into groups with similar illness representations. Data from 227 RA patients attending outpatient clinics were collected prospectively at two time points, 6 months apart. The optimal number of illness representation groups at the baseline assessment was identified using latent profile analysis. Two groups of individuals sharing similar illness perception profiles were identified. The smaller group (43%), characterised by a negative representation of their illness, attributed more symptoms to their condition and reported stronger perceptions of the consequences, chronicity and cyclicality of their condition, and lower control compared to the positive representation group (57%). Cross-sectionally, membership of the negative representation group was associated with higher levels of pain and functional disability and, longitudinally, with increases in levels of pain, functional disability and distress. These data highlight the central role of illness perceptions in RA and suggest that individuals with RA can be categorised into groups with similar illness representations.