A mismatch between self-reported physical work load and the HAQ: early identification of rheumatoid arthritis patients at risk for loss of work productivity.

OBJECTIVE 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). PATIENTS AND METHODS 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. RESULTS 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). CONCLUSION 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.