Responsiveness of patient reported outcomes including fatigue, sleep quality,
activity limitation, and quality of life following treatment with abatacept for
rheumatoid arthritis.
Author(s): Wells G, Li T, Maxwell L, Maclean R, Tugwell P.
Affiliation(s): Department of Epidemiology and Community Medicine, University of Ottawa, 451
Smyth Rd, Ottawa, Ontario, KIH 8M5 Canada. gawells@ottawaheart.ca
Publication date & source: 2008, Ann Rheum Dis. , 67(2):260-5
OBJECTIVE: To evaluate the responsiveness of patient reported outcomes (PROs),
including fatigue, sleep, activity limitation, and quality of life, in patients
with rheumatoid arthritis (RA).
METHODS: Data were considered from a randomised controlled trial comparing
abatacept (n = 258) with placebo (n = 133) on a background of DMARD treatment in
RA patients who were inadequate responders to anti-TNF therapy (ATTAIN study).
PROs assessed included SF-36, activity limitation, fatigue, and sleep. For each
outcome the treatment difference, relative per cent improvement, standardised
response mean (SRM), and relative efficiency for assessing an outcome's ability
to detect a treatment effect relative to tender joint count (TJC) were
calculated. A relative efficiency >1 suggests a measure that is more efficient
than TJC in detecting treatment effect.
RESULTS: Moderate to large SRMs (>or=0.6) were observed for the PRO measures. In
particular, SRMs (95% confidence interval) were: physician global, 0.72 (0.51 to
0.94); HAQ, 0.63 (0.42 to 0.85); SF-36 physical component score, 0.62 (0.40 to
0.83); SF-36 bodily pain, 0.68 (0.46 to 0.90); and fatigue, 0.59 (0.38 to 0.81).
Relative efficiencies for physician global (1.6), SF-36 bodily pain domain (1.4),
pain intensity (1.4), HAQ (1.2), SF-36 physical component score (1.2), fatigue
(1.1), and patient global assessment (1.04) were all more responsive than TJC.
The SF-36 mental component score (0.3), swollen joint count (0.6), activity
limitation (0.8), sleep (0.7), and C reactive protein (0.9) were less responsive.
CONCLUSIONS: Using PROs for evaluating treatments for RA can detect improvements
and will identify changes that are important to patients. In general, physical
assessments are more responsive to an effective treatment than mental
assessments.
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