Baseline Characteristics:
The patients were randomly divided into three
groups, red light group, 15 patients (10 women, 5
men); infrared light group, 18 patients (13 women, 5
men); and placebo group, 17 patients (11 women, 6
men). There was no significant age difference
between groups (P = 0.88).
Pain elevation before treatment, using SF-MPQ
sensory, affective, and total components, did not
show statistically significant between group
differences (P = 0.46, P = 0.89, P = 0.69,
respectively). No differences in pain evaluation
between the groups before treatment were found using
the PPI and VAS methods (P = 0.13, and P =
0.49, respectively). The degree of disability
before treatment, evaluated by the DIQ method, was
not statistically different between the three groups
(p = 0.68).
Pain Evaluation after Treatment:
Significant pain reduction (Table 2) was found in
the red and infrared light groups, but not in the
placebo treated group, in all three pain evaluation
methods applied in this study (P < 0.05). No
significant difference in pain relief was shown
between the group treated with red light and the one
treated with infrared light.
|
TABLE 2. MEAN PAIN RATING VALUES OBTAINED
WITH SHORT-FORM McGILL PAIN QUESTIONNAIRE
(SF-MPQ), PRESENT PAIN INTENSITY (PPI) AND
VISUAL ANALOGUE SCALE ADMINISTERED BEFORE
AND AFTER TREATMENT WITH RED, INFRARED OR
PLACEBO LIGHT EMITTERS. |
|
Pain Test |
Red
(n=15) |
Infrared
(n=18) |
Placebo
(n=17) |
|
SF-MPQ/Sensory |
|
Before (SD) |
10.40 (8.98) |
10.78 (6.28) |
8.11(4.75) |
|
After (SD) |
4.53 (6.98) |
5.27 (5.06) |
8.94 (4.84) |
|
P value |
0.0001 |
0.00001 |
0.1635 |
|
SF-MPQ/Affective |
|
Before (SD) |
3.93 (3.69) |
4.27 (2.94) |
4.47 (3.31) |
|
After (SD) |
1.60 (2.72) |
1.88 (2.32) |
4.00 (3.20) |
|
P value |
0.001 |
0.0002 |
0.1635 |
|
SF-MPQ/Total |
|
Before (SD) |
14.27 (11.81) |
15.06(7.71) |
12.47(7.62) |
|
After (SD) |
6.13 (9.63) |
7.33 (6.65) |
13.06(7.42) |
|
P value |
0.00001 |
0.00001 |
0.3220 |
|
PPI |
|
Before (SD) |
3.13 (0.99) |
3.66 (0.68) |
2.88 (1.11) |
|
After (SD) |
1.40 (0.98) |
1.16 (0.92) |
2.82 (0.88) |
|
P value |
0.00001 |
0.00001 |
0.7175 |
|
VAS |
|
Before (SD) |
6.53 (2.47) |
7.16 (2.22) |
6.23 (2.41) |
|
After (SD) |
3.33 (2.38) |
3.22 (2.62) |
6.29 (2.22) |
|
P value |
0.00001 |
0.00001 |
0.8484 |
Disability Evaluation after
Treatment: We observed significant
functional improvement in both the red and infrared
light groups as assessed by the DIQ method (Table 3,
P < 0.05). No such improvement was observed in the
placebo group. Disability indexes showed no
difference between the red and infrared groups after
the treatment.
|
TABLE 3. MEANS DISABILITY INDEX VALUES
OBTAINED WITH DISABILITY INDEX QUESTIONNAIRE
(DIQ) ADMINISTERED BEFORE AND AFTER
TREATMENT WITH RED, INFRARED, AND PLACEBO
LIGHT EMITTERS. |
|
DIQ |
Red
(n = 15) |
Infrared
(n -= 18) |
Placebo
(n = 17) |
|
Before(SD) |
0.663(0.854) |
0.617(0.56) |
0.817(0.68) |
|
After (SD) |
0.395(0.571) |
0.314(0.35) |
0.758(0.62) |
|
P value |
0.0070 |
0.0001 |
0.2440 |
Follow up: After the end of
the study, patients treated with red and infrared
light emitters requested retreatment because of pain
within 1 to 12 months (4.2 3.0 and 6.1 3.2 months
for red and infrared, respectively). The pain relief
period was significantly longer for these two groups
in comparison to the placebo group (0.53 0.62
months, P < 0.05). The difference in the period of
pain relief in the red and infrared groups was not
significantly different (P = 0.41).
All patients treated with the placebo emitters
required analgesic treatment within 2 months from
the end of the study (9 immediately, 7 within 1
month and 1 within 2 months). Only seven patients in
the other two groups required analgesic treatment
within 2 months after the end of treatment. The
remainder required treatment only after long
periods: 15 within 6 months, 10 within 10 months,
and one was free of pain 12 months after treatment. |
