To explore the combination of data on functioning and work load for early identification of patients at risk for diminished work productivity in rheumatoid arthritis (RA).
In the FIN-RACo trial, 162 patients with recent onset RA and available for the workforce were treated with either a combination of disease-modifying antirheumatic drugs (DMARDs) or a single DMARD for 2 years. Otherwise, they received routine care and were followed up for 5 years. Data on their individual income and lost work days came from official registers. Loss of productivity was computed by the human capital approach. Self-reported data on physical work demand (Finnish Institute for Occupational Health Questionnaire) at baseline and on functioning (HAQ) at 6 months were linked according to the International Classification of Functioning, Disability and Health.
Data on 112 patients were analyzable at 6 months; 35 (31%) of them had diminished capacity in functions required at paid work. Any mismatch between perceived abilities and requirements predicted future (7 through 60 months) loss of productivity - on average Euro 14,040 (95% confidence interval (CI): 9,143-20,511) per year in patients with the mismatch compared to Euro 3,043 (1,623-5,534) in those without any mismatch - and was associated with RA-related permanent work disability (hazard ratio: 11.6; 95%CI: 4.0-33.4).
Linking together self-reported data about functioning and work load helps in early identification of the RA patients at risk for loss of working days.