
64
Device Satisfaction and Stimulation Preference
At each follow-up visit, subjects specified their overall level of satisfaction with the device, and
they specified their preference with the stimulation mode at the week-24 visit. The following tables
show that most subjects were satisfied with the device therapy during both stimulation modes
(78.1%), few subjects were dissatisfied with the device (4.2%), and a similar number of subjects
had opposite responses for burst and tonic. These data are reflected more clearly in the summary
of stimulation preference, which shows that more than two-thirds of subjects (70.8%) preferred
burst stimulation over tonic stimulation. While most subjects preferred burst stimulation, 18
subjects (18.8%) still preferred tonic stimulation. This is important to note because the
investigational device is capable of both stimulation modes.
Table 41. Subject satisfaction summary at week 24
Satisfaction Level
Burst
Tonic
Burst subjects (n/N)
85/96 (88.5%)
82/96 (85.4%)
Tonic subjects (n/N)
11/96 (11.5%)
14/96 (14.6%)
Difference in satisfaction rate (burst-tonic)
3.1%
95% CI of difference in satisfaction rate (lower
bound, upper bound)
-5.3%, -11.5%
Cross-Tabulation of Satisfaction Level by Stimulation Mode
Stimulation mode
Tonic
Satisfaction level
Dissatisfied*
Satisfied**
Burst
Dissatisfied*
4/96 (4.2%)
7/96 (7.3%)
Satisfied**
10/96 (10.4%)
75/96 (78.1%)
* Dissatisfied is a combination of "very dissatisfied," "dissatisfied," and
"neither satisfied nor dissatisfied."
** Satisfied is a combination of "satisfied" and "very satisfied."
Table 42. Summary of subject stimulation preferences at week 24
Stimulation Preference
Burst
Stimulation
Tonic
Stimulation
No Preference
95% CI*
Arm 1: Tonic/Burst
37/45 (82.2%)
3/45 (6.7%)
5/45 (11.1%)
—
Arm 2: Burst/Tonic
31/51 (60.8%) 15/51 (29.4%)
5/51 (9.8%)
—
All Subjects
68/96 (70.8%) 18/96 (18.8%) 10/96 (10.4%)
60.7%,
97.7%
* 95% CI of proportion of subjects preferring burst stimulation