In previous studies of patients with advanced rheumatoid arthritis (RA), 10 years in duration, the prevalence of work disability has been estimated at as high as 50%. However, most studies examining this costly effect of RA are well over a decade old. Since then, much has changed about the disease and the nature of work. New research aims to present the latest figures.

Prompted by these changes, researchers at Boston University speculated that the high prevalence of work disability among RA patients may have changed, and they set out to provide a comprehensive, up-to-date estimate.

RA is a chronic inflammatory disease affecting the joints and, in severe cases, vital organs. Marked by pain, fatigue, and loss of dexterity and mobility, RA has been strongly associated with work disability in the US.

Featured in the April 2008 issue of Arthritis Care & Research, their data suggests that the employability outlook for men and women with advanced RA has improved since the mid-1980s.

Using the National Data Bank (NDB) longitudinal study of RA, researchers identified 5,384 subjects for analyses. All participants completed extensive surveys every 6 months between January 2002 and December 2005.

Questions covered employment status at disease onset, discontinuation of work prior to traditional retirement age (65 years), cessation of work attributed to arthritis, and, for those currently employed, work characteristics. Participants were also asked to supply demographic data and the date of RA diagnosis.

Functional limitation was determined by score on the Health Assessment Questionnaire (HAQ). Subgroups of patients were formed to assess prevalence of work disability by 5-year intervals of disease duration. In addition, the annual incidence of work disability was calculated over 3 separate time periods: 2003, 2004, and 2005.

The mean age of the RA study population was 52 years. Eighty-two percent of the subjects were women and 63% had more than a high school education. The mean disease duration was 14 years and the mean HAQ score was 1.0, indicating moderate functional limitation.

Eighty-five percent of subjects had been employed at disease onset and 56% were currently employed. Nearly three-quarters of these employed subjects worked full-time, 41% held professional or managerial jobs, and 16% were self-employed. Among subjects who were not employed, 43.5% were disabled; the remainder described themselves as either retired, full-time homemakers, or unemployed.

The prevalence of work cessation before age 65 increased with years of disease duration. This ranged from 23% among patients with relatively early RA—1 to 3 years, to 35% in those living with RA for a decade, and 51% in those with RA for at least a quarter century.

The prevalence of arthritis-attributed work cessation also increased with disease duration but was somewhat lower, beginning with 14% in subjects with 1 to 3 years, increasing to 29% in subjects with 10 years, and culminating at 42% in those with RA for 25 years or more.

The annual incidence of premature work cessation was 12% in 2003, 9% in 2004, and 9% in 2005. Incidence of work cessation directly attributed to arthritis was even lower, about 6 percent per year, and decreased slightly over the 3 years. Thirty-nine percent of the subjects who stopped working later returned to work over the course of the study period.

Supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, this study suggests a decline in the prevalence of RA work disability, particularly among patients with 10 years of disease duration, since the mid-1980s.

As its authors note, there are several possible explanations for this, including declines in both the unemployment rate and the physical demands of jobs in the US, as well as improvements in the treatment of RA. Among other notable findings, many cases of work disability were temporary and many may have had little relationship to RA.

[Source: Wagner S. Wiley-Blackwell]