
65
Psychosocial Health and Physical Function Measures
The PGIC questionnaire was completed at the week-12 and week-24 visits and was used to
evaluate the subject’s impression of change since beginning the study treatment. The following
table shows the summary of responses to this questionnaire pooled across the two arms. Overall,
the proportion of subjects whose global impression was moderately better, better, or a great deal
better was comparable between the two stimulation modes (72/97 for burst versus 71/96 for
tonic).
Table 43. Summary of PGIC questionnaire
PGIC
Burst
Tonic
No change (or condition has got worse)
6/97 (6.2%)
1/96 (1.0%)
Almost the same, hardly any change at all
7/97 (7.2%)
11/96 (11.5%)
A little better, but no noticeable change
7/97 (7.2%)
3/96 (3.1%)
Somewhat better, but the change has not made any real
difference
5/97 (5.2%)
10/96 (10.4%)
Moderately better, and a slight but noticeable change
20/97 (20.6%) 16/96 (16.7%)
Better, and a definite improvement that has made a real and
worthwhile difference
35/97 (36.1%) 43/96 (44.8%)
A great deal better, and a considerable improvement that has
made all the difference
17/97 (17.5%) 12/96 (12.5%)
The following table presents the physical and mental component scores for the SF-36 quality of
life survey. Burst stimulation had higher pooled scores than tonic stimulation with a difference of
0.4 for the physical component score and 0.7 for the mental component score. It is important to
note that baseline scores for the mental component of the SF-36 (48.7) are near the normative
mean (50.0) for this subscale (Ware, 2000), indicating that the subject’s quality of life based on
mental health was about the same as the general population (Bell, 2015; Verkerk, 2015) and
were not representative of chronic pain patients (Elliott et al, 2003).
Table 44. Components of SF-36 quality of life physical and mental scores
Randomization
Arm 1:
tonic/burst
Arm 2:
burst/tonic
Pooled
Physical Component Scores
Baseline
Mean ± SD (N)
29.0±6.5 (42)
28.3±8.3 (47)
28.6±7.5 (89)
Minimum, Median, Maximum
16.2, 27.7, 45.6
12.9, 27.7,
49.3
—
Burst
Mean ± SD (N)
37.3±8.4 (42)
35.3±8.3 (47)
36.2±8.4 (89)
Minimum, Median, Maximum
23.2, 37.8, 53.6
20.7, 34.8,
51.2
—