Background/Purpose: To describe working status in an ERA population in the first year of disease, and factors associated with improved work productivity. 

Methods: Patients in the Canadian Early Arthritis Cohort who completed the Work Productivity and Activity Impairment (WPAI) questionnaire at baseline and month 12 (commencing in 2010) were included.  Differences in working status at baseline were compared using chi-square or student’s t-tests.  A change in employment status and overall activity impairment was calculated as change from baseline to month 12. A change in absenteeism (work hours missed) and presenteeism (impact of RA on work productivity) was only calculated for those working at baseline.  Multivariate logistic regression analyses tested whether age, sex, symptom duration, DAS28 score, HAQ-DI or treatment at month 6 were associated with improvements in WPAI domains. 

Results: Of 2524 patients in the cohort, 729 had completed at least one WPAI questionnaire.  Of these, 190 were eligible (423 did not have serial WPAI and 306 were missing month 6 variables for analysis).  At baseline, the 190 patients had mean age 56 years, symptom duration 5.6 months, baseline DAS28 score 4.85; 110 were in paid employment at baseline. Individuals not in paid employment at baseline less frequently had high school or college education, had lower income, were older, had moderate-to-high DAS28 scores, and demonstrated higher HAQ-DI scores. Improvements in WPAI domains are shown (Table).  Among working individuals, by 12 months, 78% had an improvement in working hours missed, 67% reported improved productivity and 72% had reduced activity impairments. The largest change occurred for absenteeism (9.57 fewer hours/week missed). Younger age (OR 0.93, CI 0.89-0.98), DAS28 remission (OR 10.52, CI 1.4-79) and higher HAQ-DI at month 6 (OR 4.01, CI 1.2-13.1) were associated with gaining employment by month 12. DMARD or biologic use at month 6 was not associated with change in WPAI domains but corticosteroid use was negatively associated with presenteeism (OR 0.23, CI 0.06-0.89). 

Conclusion: Differences in demographic and disease-related variables exist between ERA patients who are working versus those who are not.  The majority of working individuals show improvements in WPAI domains over time but establishing the minimum clinically important difference for these domains is needed to help guide clinical interpretability. The impact of disease activity and functional ability on work productivity warrants further exploration in larger samples. 

Table. Mean (SD) in WPAI domain scores at baseline, month 12 and change from baseline to month 12.