Combination Therapy and the Outcome of Rheumatoid Arthritis RA Frederick Wolfe and Kaleb Michaud

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Multivariate Predictors of H. Zoster
Combination Therapy and the Outcome of Rheumatoid
Arthritis (RA) Frederick Wolfe and Kaleb
Michaud National Data Bank for Rheumatic
Diseases, Wichita, KS
The distribution of the PAS The Patient Activity
Scale (PAS) (J Rheumatol. In press) defines
levels of clinical activity and predicts
treatment change and mortality. The PAS scale
performs about as well as the SF-36 composite
scale. The PAS i s formed by multiplying the HAQ
by 3.33 and then dividing the sum of the VAS
pain, VAS global and HAQ/HAQ-II by 3. This yields
a 0-10 scale
Abstract PURPOSE. Recommendations by authors and
the results of clinical trials have suggested
benefit from combination therapy. However,
combination therapy may be influenced by adverse
effects, difficulty of use and cost issues. The
rate of combination therapy use is not known
accurately, nor is the outcome of this therapy.
We used a longitudinal data bank to measure the
rate and outcome of combination
therapy. METHODS. In 15,874 patients
participating in a long-term outcome study of RA,
we identified rates of non-transient use of
combination DMARD or biologic therapy from 1998
through 2004. Health Assessment Questionnaire
(HAQ) scores were used to define functional
status and the Patient Activity Scale (PAS), a
standardized average of HAQ, VAS pain and VAS
global that was transformed to a 0-10 scale, was
used to measure disease activity. The rate and
outcome of monotherapy no DMARD/no biologic
therapy patients was obtained at the most recent
study observation using 12,690 patients who were
enrolled only from the practices of US
rheumatologists. RESULTS. Table 1 displays
important combinations of DMARD and biologic
therapy. Combination therapy was common among
patients using biologics. For ETA 64.1 used
combinations that included MTX, LEF or AZA. That
percentage was increased to 90.1 when INF was
the base drug. Combination use of more than one
biologic agent was rare (1 or less). By
contrast, DMARD combinations that did not include
biologics were more common. Among MTX users,
22.0 used HCQ and 14.5 used LEF. Among LEF
users, 37 used MTX and 18.2 used HCQ. The
triple drug combination of MTX, HCQ and SSZ was
used rarely (1.9). Monotherapy was often used.
At the last observation, MTX alone was used by
21.4, HCQ by 13.8, SSZ by 1.6, LEF by 3.1,
for a total monotherapy use with these drugs of
39.9. However, no therapy was used by 20.2.
Patients using the most common type of
combination therapies (Table 1) had HAQ and PAS
scores of approximately 1.1 and 3.8. Among
monotherapies the HAQ and PAS were MTX 1.1 and
3.5, CQ 0.9 and 3.2, SSZ 0.8 and 3.1, LEF 1.2 and
4.0, and no therapy 1.1 and 3.9. CONCLUSIONS
Among RA patients, approximately 40 use mono
DMARD therapy and 20 use no DMARD therapy.
Combination therapy is the rule for biologics,
and ranges from 64 for etanercept to 90 for
infliximab. There is little difference in HAQ and
PAS scores among users of the common combinations
and users of monotherapy, except for monotherapy
with HCQ. These data suggest that there is an
average population level of HAQ and PAS that is
achievable by current therapies. It is likely
that at a population level patients and
physicians tend to use the least powerful,
least complicated and least expensive treatments
if they will produce acceptable results based on
current expectations.

Mono DMARD therapy is used by 40 of RA patients

The use of combination therapy in RA

The distribution of the HAQ

Current therapy in RA ?
National Data Bank for Rheumatic Diseases