Predictors of work disability during the first 3 years after diagnosis in a national rheumatoid arthritis inception cohort
- Tor Olofsson1,2,
- Ingemar F Petersson1,2,
- Jonas K Eriksson3,
- Martin Englund2,4,
- Julia F Simard3,
- Jan-Åke Nilsson1,
- Pierre Geborek1,
- Lennart T H Jacobsson5,6,
- Johan Askling3,
- Martin Neovius3
- 1Section of Rheumatology, Department of Clinical Sciences, Lund University, Lund, Sweden
- 2Department of Orthopedics, Musculoskeletal Sciences, Clinical Sciences Lund, Lund University, Lund, Sweden
- 3Clinical Epidemiology Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
- 4Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, Massachusetts, USA
- 5Department of Rheumatology and Inflammation Research, Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- 6Section of Rheumatology, Department of Clinical Sciences, Lund University, Malmö, Sweden
- Correspondence to Dr Tor Olofsson, Section of Rheumatology, Department of Clinical Sciences, Lund University, Lund SE-22185, Sweden;
- Accepted 24 February 2013
- Published Online First 21 March 2013
Objective To identify predictors of sick leave and disability pension in patients with early rheumatoid arthritis (RA).
Methods Individuals aged 19–59 years diagnosed with early RA (≤12 months symptom duration) were identified in the Swedish Rheumatology Quality Register (1999–2007; n=3029). We retrieved days of sick leave and disability pension from the Swedish Social Insurance Agency and baseline predictors of total work days lost during 3 years after RA diagnosis were investigated using linear regression. Due to effect modification by baseline work ability (defined as work days lost the month before diagnosis), analyses were stratified into three categories: full=0 work days lost the month before diagnosis; partial=1–29 work days lost; and none=30 work days lost.
Results 71% of patients with full baseline work ability still had full work ability after 3 years compared with 36% (p<0.001) and 18% (p<0.001) of those with partial and no work ability at baseline, respectively. Elevated baseline levels of HAQ and DAS28, higher age, lower education level and unemployment were associated with more work days lost during 3 years in all strata of baseline work ability (all p<0.05). In a separate analysis, more objective variables (ESR, CRP and swollen joints) were not. Generally, the largest regression coefficients were seen for patients with partial baseline work ability.
Conclusions Work ability at RA diagnosis was the most important predictor of 3-year sick leave and disability pension. Taking this into account, HAQ, DAS28, age and education level were also significant predictors, whereas ESR and CRP were not.