Patient_Reported_Outcome_Measures_in_Rheumatic_Diseases

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Validation Data for VAS Pain in Acute Gout

Several studies have investigated whether VAS pain is a valid measure in acute gout
by examining the effect of various therapies on VAS pain. Studies compared various
treatments to each other or examined pre-to-post treatment change in VAS pain with
a single intervention. These studies (summarized in the section that follows) have
demonstrated the discriminative ability of pain measures in gout for different treat-
ments and for different states with the same treatment.
Effect of treatments of acute gout on VAS pain (Table 9.3 ): A randomized study
(RCT) compared oral prednisolone with oral diclofenac plus indomethacin in 90
patients with acute gout. Mean age was 65 years. After 2 weeks, the mean difference

Table 9.3 (continued)

Drugs/drug

comparisons Outcome

VAS score

change/absolute

in group 1

VAS score

change/absolute in

group 2

Mean change in

VAS scores

Subcutaneous

canakinumab vs.

intramuscular

triamcinolone

acetonide [ 50 ]

Pain at 72 h 35.7 mm 25.0 mm Mean

difference:

10.7 mm c

95 % CI: −15.4

to −6.0;

N = 443 p < 0.0001

Drugs/drug

comparisons

Outcome VAS score

pretreatment

VAS score

posttreatment

Mean change in

VAS scores

Intra-articular

triamcinolone

acetonide pre vs.

post

Pain at 48 h NR Mean reduction

from 88 (pre) to

0 (post)

N = 19

Subcutaneous

anakinra pre vs. post

[ 51 ]

Pain

reduction at

day 4

Pre: 73.5 mm Post: 25.0 mm Mean

reduction:

48.5 mm d

IQR: 70.0 to 80.0 IQR: 20.0 to 32.5

N = 40 p < 0.0001

Intramuscular

ketorolac pre vs.

post [ 52 ]

Pain

reduction at

90 min

Pre: 64.3 mm Post: 10.1 mm Mean
reduction:
54.2 mm e
N = 9 p < 0.01
VAS visual analog scale, MD mean difference, NR not reported, NSAIDs nonsteroidal anti infl am-
matory drugs, NNTB number needed to treat to benefi t
a The difference in mean pain score was at no time more than 13 mm, which was unlikely to be
clinically relevant according to the authors
b 4 of 16 patients required a second I-injection (I = intervention), 9 of 14 a second C injection
(C = control). 3 patients required a third C-injection
c Absolute improvement: 11 % lower with canakinumab (15 to 6 % lower). Relative % change: 14 %
more improvement with canakinumab (8 to 21 % more improvement) 2 NNTB 7 (95 % CI 5 to 12)
d Retrospective study
e No side effects were reported

9 PROMs for Gouty Arthritis