Work loss, earnings, and educational attainment in patients with rheumatoid arthritis and juvenile idiopathic arthritis

Chronic inflammatory diseases such as rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA) can have lasting effects on individuals' ability to work and earn a living. While advancements in treatment have improved disease management, their impact on long-term economic outcomes remains uncertain. This thesis examines how RA and JIA affect earnings, work loss, and educational attainment, using Swedish nationwide register data. Individuals with RA and JIA were matched to same-sex siblings (RA) or general population comparators (JIA) based on birth year, sex, and location.

Study I compared the earnings of 2,433 RA patients (2006–2017) to those of their same-sex siblings. We found that patients with RA, compared to siblings, earned 5.4% less per year after diagnosis. Stratifying by diagnosis year demonstrated a more pronounced reduction among those diagnosed earlier (2006–2010) (8.2%). Patients diagnosed more recently (2011–2017) showed no statistically significant earnings decline, suggesting that improved treatment and earlier intervention may have mitigated economic losses.

Study II investigated work loss, measured as sick leave and disability pension, in a similar RA cohort diagnosed between 2006 and 2020, with slightly extended inclusion and follow-up compared to Study I. In the first year after diagnosis, patients diagnosed between 2006 and 2011 had 47 additional days of work loss per year, and patients diagnosed between 2012 and 2020 had 26 additional days of work loss per year. Work loss was highest in both cohorts in the first year after diagnosis but declined over time. From years 2 to 10 after diagnosis, patients diagnosed between 2006 and 2011 had an additional 29 days annually, and patients diagnosed between 2012 and 2020 had an additional 11 days annually.

Study III focused on earnings and work loss in 4,737 individuals diagnosed with JIA, matched to 23,645 general population comparators (2001–2017). Patients with JIA had 5.5% lower earnings than their peers, with the largest gap occurring before age 26. While earnings differences diminished over time, work loss remained consistently higher, with patients with JIA having an average of 11 additional sick leave or disability days per year. A subgroup with more severe disease accounted for the majority of work loss. Among those with systemic JIA (sJIA), a particularly severe form of the disease, work loss was even higher, and earnings were lower compared to other patients with JIA.

Study IV examined educational attainment among 4,254 individuals diagnosed with JIA (2001–2017), matched to 4,254 general population comparators. Over up to 16 years of follow-up (median 4 years), 83.1% of patients with JIA and 83.0% of comparators completed high school or more (hazard ratio [HR] 0.99, 95% CI: 0.97–1.01). Similarly, 34.5% of patients and 34.1% of comparators pursued some post-secondary education or more (HR 1.02, 95% CI: 0.97–1.08). No differences were observed by sex, parental education, or diagnosis period. Among individuals followed until age 30, educational outcomes remained comparable: 85.9% of patients with JIA and 86.1% of comparators completed high school, and 48.1% versus 49.9% had post-secondary education. The conditional odds ratio was 0.98 (95% CI: 0.71–1.36) for a high school degree and 0.92 (95% CI: 0.73–1.15) for post-secondary education.

To summarize, we found clear improvements in earnings and work loss among patients with RA diagnosed in more recent years, though work loss remained elevated overall, driven by a small subset of patients. In JIA, earnings and employment were lower than those of the general population comparators, with the differences narrowing after age 26. Patients with JIA had consistently higher work loss, about 11 additional days per year, also driven by a more severely affected subgroup. Educational attainment in patients with JIA was comparable to the general population, with similar proportions completing high school or post-secondary education by age 30. These findings suggest that advances in diagnosis and treatment may have improved long-term socioeconomic outcomes.

List of scientific papers

I. Miller H, Neovius M, Askling J, Bruze G. Impact of Incident Rheumatoid Arthritis on Earnings: A Nationwide Sibling Comparison Study. Rheumatology (Oxford). 2024 Oct 16:keae535. Epub ahead of print. Erratum in: Rheumatology (Oxford). 2025 Jan 06. https://doi.org/10.1093/rheumatology/keae535

II. Miller H, Bruze G, Johansson K, Askling J, Neovius M. Incident Rheumatoid Arthritis and Work Loss: A Nationwide Sibling Comparison Study. [Submitted]

III. Miller H, Neovius M, Sundberg E, Askling J, Bruze G. Juvenile Idiopathic Arthritis, Earnings and Work Loss: A Nationwide Matched Cohort Study. Arthritis Care Res (Hoboken). 2025 Mar 16. doi:10.1002/acr.25522. Epub ahead of print. https://doi.org/10.1002/acr.25522

IV. Miller H, Neovius M, Johansson K, Askling J, Bruze G. Juvenile Idiopathic Arthritis and Attained Education: A Nationwide Matched Cohort Study. [Manuscript]