Substantial, Clinically Important Decreases in Disease Severity

1
Substantial, Clinically Important Decreases in
Disease Severity Work Disability are Associated
with Increased Levels of Education in Patients
with Rheumatic DiseasesFrederick Wolfe1, Kaleb
Michaud1, Jodi Messer2, Theodore
Pincus31National Data Bank for Rheumatic
Diseases, Wichita, KS2Wichita State University,
Wichita, KS3Vanderbilt University, Nashville, TN
Abstract
Table 2 The Association of Education with
Erythrocyte Sedimentation Rate in 1988 Rheumatoid
Arthritis Patients from Clinical Practice
Background. Although formal education is a
primary measure of socio-economic status that is
significantly associated with the incidence,
prevalence, morbidity and mortality of most
chronic diseases, it tends to be a neglected
variable in rheumatic disease clinical trials and
observational studies. To better understand its
clinical significance, we investigated the extent
to which education is associated with clinical
status and outcome in the 3 most common rheumatic
disorders, rheumatoid arthritis (RA),
osteoarthritis (OA) and fibromyalgia. Methods.
11,748 patients with rheumatic diseases (RA
8,896, OA 2,299, fibromyalgia 486) completed
a detailed assessment of demographic, clinical
status and treatment variables. Patients were
classified into 5 groups according to years of
formal education 0-8 (ED8), 9-11 (ED11), 12
(ED12), 13-15 (ED15), and 16 or gt (ED16). Rates
and means scores were adjusted for age, sex, and
ethnic origin, and tests of linear trend were
performed using OLS and logistic
regression. Results. In general, consistent
associations with years of formal education were
seen across all 3 disorders, and combined results
are presented. Among patients less than 65 years
of age, 26.5 were work disabled and 22.1
received Social Security disability payments.
Persons with ED12 were odds ratio (95 CI) 2.0
(1.9, 2.7) and 2.1 (1.7, 2.2) times more likely
to be disabled or receive SS disability than
those with ED 15 and ED16, while those with ED12
were less likely to be disabled or receiving
disability pension than those with less
education, OR 0.33 (0.26, 0.43) and 0.45 (0.35,
0.59), for Ed11 and ED8, respectively. Across all
diagnoses, HAQ, pain global, RADAI, fatigue,
helplessness, and QOL were increasingly more
abnormal with decreasing levels of education. The
full range of HAQ differed by as much as 0.5
units, a greater difference than has been
reported for DMARD or biologic therapies in
clinical trials. Furthermore, education had a
strong protective effect on the number of
comorbid conditions, a recognized predictor of
disability and premature mortality. In addition,
COX-2 therapy and etanercept were positively
associated with higher education levels, while
prednisone, analgesics and opiods were negatively
associated with education level. The pattern of
costs was complex, with drug costs being higher
in the most educated, and hospital and
outpatients costs being higher in the least
educated patients. Conclusion. Increased levels
of formal education beyond high school confer a
substantial life-long benefit to patients with
rheumatic diseases, while less than the modal
education level extracts a similarly strong
penalty. Education exerts a broad effect across
disease activity and status variables, work
disability, and treatment, at levels that are
clinically significant and meaningful.
Data from 1988 randomly selected observations
from 1988 rheumatoid arthritis patients in the
Wichita clinical data bank. By logistic
regression, the difference between groups is
significant at plt0001.

Table 3. Association of Rheumatic Disease
Outcomes with Education Level and Disability
Status in 9,034 Patients in the National Data
Bank for Rheumatic Diseases


Methods
This study was performed using the National Data
Bank for Rheumatic Diseases (NDB). The NDB is a
rheumatic disease research data bank in which
patients complete detailed self-report
questionnaires at 6 month intervals. The
characteristics of the NDB have been reported
previously. Patients in the NDB are recruited
from two sources 1) non-selected patients from
the practices of 248 US rheumatologists and 2)
patients enrolled as part of pharmaceutical
company sponsored registries. Patients in the
current study are those with rheumatoid arthritis
(RA), osteoarthritis of the hip or knee (OA), and
fibromyalgia. All diagnoses were made by
referring the referring rheumatologists. Patients
who were recruited as part of pharmaceutical
company registries were excluded to avoid
possible bias. After this exclusion, the study
sample consisted of 9,034 patients of whom 69
had RA, 24 had OA, and 7 had fibromyalgia.
Patients were studied at their most recent
observation. To obtain data on the relationship
of erythrocyte sedimentation rate (ESR) on
arthritis outcomes, we also studied all RA
patients in the Wichita data bank (N1988), as
that data bank has such laboratory data.
Disabled self classified work status as disabled
or stopped work or retired early because of
illness. Total joint arthroplasty restricted to
patients with rheumatoid arthritis. Restricted to
patients between 25 and 65 years of age. Analyses
are adjusted for age, sex, diagnosis, and ethnic
origin.