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score could also be computed with a
formula given in the POMS user's manual.
Following the pretests, subjects in groups I and II were taught how to
use the CES unit, and they were instructed to use it every day for 1
hour over a 3-week period. At the end of that time, they returned to
the clinic for posttreatment evaluations as above. Group III subjects
were given no CES device, but they were told to return in 3 weeks for
retesting.
All subjects were told that those sham-treated and placebo-controlled
patients who did not receive treatment during the study would be
provided CES treatment after the conclusion of the double-blinded part
of the study if they wished. That treatment would be in an open,
non-double-blind clinical trial in which each patient would be
provided an Alpha-Stim CES unit to use at home, and they would be
allowed to adjust the stimulation intensity to maximum comfort level.
During the study, a clinical staff member called each member of groups
I and II once a week to check on compliance. It was checked again when
subjects came in for final study evaluations.
RESULTS
No differences were found on the 12 pretest measures among the three
study groups at the beginning of the study. The question sometimes
arises in studies of this kind if the study outcome might be
attributed to differences in patient medications in the various study
groups. We did not control specifically for that, assuming that the
randomization of patients into the three groups would scatter this
effect more or less equally across the groups. These results indicate
that the assumption was correct.
The double-blind condition depended on the stimulation current being
below sensation threshold in most patients so that the patients would
not know whether or not
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they were actually receiving treatment. CES electrodes
contain a felt covering that is thoroughly wetted prior to placing it
on the patient, and many patients experience the cold covering as
stimulation, and they report a feeling of tingling, even after the
moistened felt has warmed to skin temperature. Be-cause sham-treated
patients have been just as likely to report this sensation as have
treated patients in past studies, we did not ask for this information
from the patients. After the study, however, four patients volunteered
the information that they had felt a tingling sensation from the
electrodes during the study. Two were later found to be sham treated
and two had received actual treatment.
The double-blind treated group had significant mean gains on tender
point score (t = 2.27, p < 0.01), self-rated pain (t = 3.04, p <
0.002), quality of sleep (t = 2.05, p < 0.02), feeling of well-being
(t = 1.67, p < 0.05), and quality of life (t = 1.92, p < 0.03). There
were 38 degrees of freedom on each analysis. The sham-treated and
placebo-controlled groups had no positive gains during the study.
Since subsensation CES at 100 ľA is a very small level of stimula-
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tion, it was decided also to compare the treated
subjects in the double-blind study against those in the poststudy open
clinical group who reported having used an intensity of stimulation
that was above sensation level.
Only 23 of the 40 control patients opted for actual CES treatment
after their participation in the double-blind part of the study. When
the test scores of those who came in for the additional treatment were
compared with those of the group not asking for additional treatment,
no differences were found on their 12 pretest measures except on the
self-rated quality of life, in which those requesting treatment had
significantly lower scores (t = 2.48, df = 38, p < 0.02).
The four groups that were analyzed are shown in Figure 1, where it can
be seen that there was no positive placebo effect among the
sham-treated patients on the scores presented. One-tailed analyses
were performed to see if the observed mean reductions of the scores
among the treated groups were significant.
The open clinical group had significant gains on tender point scores
(t = 3.27, p < 0.001), self-rated pain (t = 1.68, p < 0.05), qual-
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Cranial
Electrotherapy Stimulation