Factors influencing work disability in psoriatic arthritis: first results from a large UK multicentre study

The aim of this study was to determine the extent to which structural damage, clinical disease activity, demographic and social factors are associated with work disability (WD) in PsA.

Four hundred patients fulfilling CASPAR (Classification Criteria for Psoriatic Arthritis) criteria for PsA were recruited from 23 hospitals across the UK. Demographic, socio-economic, work, clinical and radiographic data were collected. WD was assessed with the Work Productivity and Activity Impairment Specific Health Problem (WPAI-SHP) questionnaire reporting WD as a percentage of absenteeism (work time missed), presenteeism (impairment at work/reduced effectiveness) and work productivity loss (overall work impairment/absenteeism plus presenteeism). Logistic and linear regressions were conducted to investigate associations with WD.

Two hundred and thirty-six participants of any age were in work. Absenteeism, presenteeism and productivity loss rates were 14% (s.d. 29.0), 39% (s.d. 27.2) and 46% (s.d. 30.4), respectively. Ninety-two (26%) participants of working age were unemployed. Greater age, disease duration of 2-5 years and worse physical function were associated with unemployment. Patients reported that employer awareness and helpfulness exerted a strongly positive influence on remaining in employment. Higher levels of global and joint-specific disease activity and worse physical function were associated with greater levels of presenteeism and productivity loss among those who remained in work.

Reduced effectiveness at work was associated with measures of disease activity, whereas unemployment, considered the endpoint of WD, was associated with employer factors, age and disease duration. A longitudinal study is under way to determine whether treatment to reduce disease activity ameliorates WD in the real-world setting.