Benign or painful? The interpretation of pain and fear of progression in rheumatoid arthritis.

People with chronic pain tend to interpret ambiguous information as health-related, more so than people without. In this study, we aimed to investigate whether people with rheumatoid arthritis (RA) exhibit this interpretation bias and whether it is associated with fear of disease progression (FoP). The interpretation biases of people with RA (n = 164) were compared with an age- and gender-matched control group. We hypothesized that (1) people with RA would have larger interpretation biases than people without; (2) those who scored in the clinical range for FoP would have larger interpretation bias than those who did not; (3) interpretation bias would moderate the relationship between pain severity and FoP; and (4) interpretation bias would explain variance in FoP above and beyond other established predictors. Our results confirmed that people with RA were more likely to interpret ambiguous information as health-related compared with people without RA. This effect was more pronounced for the RA subgroup with clinically significant FoP than those scoring in the normal range. We did not find evidence to suggest interpretation bias moderated the relationship between pain and FoP or that FoP added to the variance of other known predictors. Our results indicate that interpretation bias is common amongst people with RA and is associated with FoP. Further research is required to illuminate the exact nature of this relationship.