Objective: There is a need to better define symptom characteristics associated with arthritis development in individuals at risk of rheumatoid arthritis (RA). We investigated whether reported symptoms in at-risk individuals could predict arthritis development and whether predictive symptoms differed between seropositive and seronegative at-risk individuals.
Method: At-risk individuals from four cohorts (Netherlands, UK, Sweden, and Switzerland) completed the Symptoms in Persons At Risk of Rheumatoid Arthritis (SPARRA) questionnaire. Participants had either (i) anti-citrullinated protein antibodies and/or rheumatoid factor, or (ii) relevant symptoms with or without RA antibodies. Follow up was ≥ 24 months or until clinical arthritis development. Stepwise forward selection created SPARRA prediction models for the combined group and for a seropositive subgroup.
Results: Of 214 participants, the mean age was 50 years, 67% were female, and 27% (n = 58) developed clinical arthritis after a median time of 7 months. Four symptoms predicted arthritis development: self-reported joint swelling, joint pain moving from side to side (combined group only), feeling pins and needles in the joints, and often feeling fatigued (predicting non-arthritis).
Conclusion: Specific symptoms can provide useful information to estimate a person's RA risk. Differences in predictive symptoms between seropositive and seronegative at-risk individuals need to be further investigated. Future research is needed to determine whether changes in symptoms over time improve prediction and to determine the value of SPARRA in optimizing the selection of individuals who need to consult a rheumatologist.