Rheumatoid arthritis (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.
In previous studies of patients with advanced RA, 10 years in duration, the prevalence of work disability has been estimated at as high as 50 percent.
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.
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.
Featured in the April 2008 issue of Arthritis Care & Research (http://www.interscience.wiley.com/journal/arthritis), 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. 82
percent of the subjects were women and 63 percent 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. 85 percent of subjects had been employed at disease onset and 56 percent were currently employed.
Nearly three-quarters of these employed
subjects worked full-time, 41 percent held professional or managerial
jobs, and 16 percent were self-employed. Among subjects who were not
employed, 43.5 percent 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 percent among patients
with relatively early RA - 1 to 3 years, to 35 percent in those living
with RA for a decade, and 51 percent 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 percent in subjects with 1 to 3 years, increasing to 29 percent in subjects with 10 years, and culminating at 42 percent in those with RA for 25 years or more.
The annual incidence of premature work
cessation was 12 percent in 2003, 9 percent in 2004, and 9 percent 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. 39 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.
"Work disability among persons with RA in the US is still a
substantial problem," observes the study's lead author Saralynn
Allaire, ScD. "However, our data in comparison with previous US studies
also suggest there has been some improvement over the past 15 to 20
years in those with longer-standing disease."
As Allaire acknowledges, this study has limitations.
"Because subjects with mild RA may not be
fully represented in the NDB sample and may have less work disability,
the actual RA work disability prevalence could be lower than we found.
On the other hand, because NDB subjects have higher educational
attainment and are more often white than the US population, and because
these characteristics offer employment advantages, the actual RA work
disability rate may be higher than we found."