One hundred and twenty two patients were randomised. Three women could not complete the study (asthma, change of work, and death in the family), and two were excluded because they used other treatments during the trial. Ten women dropped out with motivation problems or adverse effects: two from pelvic floor muscle training (one motivation problem, one because of travel time to the training group), seven from electrical stimulation (two because of pain, one for bleeding, and four through lack of motivation), and one from vaginal cones (vaginal bleeding). This left 107 participants: 30 in the control group, 25 in the pelvic floor exercise group, 25 in the electrical stimulation group, and 27 in the vaginal cones group (fig ).
Figure 1 Trial profile of 130 women recruited to study of treatment of stress incontinence
At baseline there were no significant differences between the groups in any of the background characteristics such as age, body mass index, duration of symptoms, pelvic floor muscle strength, urodynamic assessment, or degree of leakage (table ).
Background and outcome variables before treatment. Values are means (SD) unless stated otherwise
Compliance with treatment
Mean (SE) adherence with treatment was 93% (1.5%) for pelvic floor muscle training, 75% (2.8%) for electrical stimulation, and 78% (4.4%) for vaginal cones. Adherence with pelvic floor muscle training was significantly greater than with electrical stimulation or vaginal cones (P<0.001 and <0.002, respectively). The difference between the electrical stimulation and cone groups was not significant.
Changes after treatment
Figure shows details of the change in strength of the pelvic floor muscles. There was no significant change in the control group, but significant improvement was seen after treatment in the other groups. Only in the pelvic floor exercise group, however, was the improvement significant when it was compared with the control group (P<0.01). The change in the strength of pelvic floor muscle was significantly greater (P=0.03) in the pelvic floor exercise group (11.0
O (95% confidence interval 7.7 to 14.3) before test v
O (15.3 to 23.1) after test) compared with electrical stimulation (14.8
O (10.9 to 18.7) v
O (13.3 to 23.9)) and vaginal cones (11.8
O (8.5 to 15.1) v
O (11.1 to 19.7)). There was no difference in changes of strength between the electrical stimulation and vaginal cones groups (P=0.90). Intention to treat analyses did not change the results.
Figure 2 Change in strength of pelvic floor muscles in control group and treatment groups
Analysis with Kruskal-Wallis test showed significant differences between groups in changes in all outcome variables except the 24 hour pad test (table ). Table shows the difference between active and control treatment in changes from baseline to 6 months with 95% confidence intervals for efficacy variables.
Mean change (95% confidence interval) in measures of stress incontinence from baseline to 6 months
Differences (95% confidence intervals) between active and control treatment in change in stress incontinence measured by efficacy variables from baseline to 6 months
There were also significant differences in change between the pelvic floor exercise group and the control group according to the results of the pad test with standardised bladder volume (P=0.02), episodes of leakage in 3 days (P<0.01), social activity index (P<0.01), and leakage index (P<0.01). The difference between electrical stimulation and control was significant for episodes of leakage in 3 days (P=0.02), social activity index (P<0.01), and leakage index (P<0.04) (table ). The difference between the vaginal cones group and the control group was significant for social activity index (P=0.04) and leakage index (P=0.02) (table ). The pelvic floor exercise group improved significantly more than the electrical stimulation group measured by pad test with standardised bladder volume (reduction in urine leaked 30.2
7.4 g; difference 22.8 (3.8 to 41.8); P=0.02) and leakage index (0.9 v
0.2 lower; difference−0.7 (−0.4 to −1.0); P<0.01) and significantly more than the vaginal cones group in pad test (reduction in urine leaked 30.2
14.7 g; difference −15.5 (−34.1 to 3.1); P<0.01), episodes of leakage over 3 days (1.2 fewer v
0.8 more; difference −2.0 (−41.0 to 0.1); P=0.03), and leakage index (0.9 v
0.3 lower; difference −0.6 (−0.9 to −0.3); P<0.01). There were no significant differences between the electrical stimulation and vaginal cones groups in any outcome variable. There were no significant changes in maximum urethral pressure or maximum closure pressure for any group.
Objective cure (
g leakage on the pad test with standardised bladder volume) was achieved by two women in the control group, 11 in the pelvic floor exercise group, seven in the electrical stimulation group, and four in the vaginal cones group (P=0.02).
Subjective cure (number of women stating that the condition was “unproblematic” after the treatment) was reported by one woman in the control group, 14 in the pelvic floor exercise group, three in the electrical stimulation group, and two in the vaginal cones group. When corrected for baseline values the change in the pelvic floor exercise group was significantly greater than the change in the other groups (P<0.001).
Table shows subjective improvement after intervention. Significantly more women in the exercise group reported being continent or almost continent (P<0.001) than in the other groups. Fourteen of the 30 participants in the control group chose to use the continence guard. Four felt completely dry when wearing the guard, and five felt somewhat better. Three participants in the control group and two in the electrical stimulation group considered themselves worse after treatment.
Subjective assessment of improvement in stress incontinence according to treatment
Twenty eight women in the control group, four in the pelvic floor exercise group, 19 in the electrical stimulation group, and 23 in the vaginal cones group wanted further treatment, apart from the one they had been randomised to, after the trial period. The difference between groups was significant in favour of the pelvic floor exercises (P<0.001).
The results according to the intention to treat analysis showed virtually the same results as the treatment analyses. The only group that came out somewhat weaker when compared with the control group was the electrical stimulation group. Only the variable of leakage in 3 days showed nominally significant differences in change from baseline compared with the control group (P=0.047). Improvement on the social activity index also became significant in favour of exercises compared with electrical stimulation.
Adverse effects and treatment tolerance
There were no side effects reported for pelvic floor exercises. In the electrical stimulation group two participants reported smarting (one tenderness and bleeding, one discomfort), and eight women reported motivation problems and difficulties in using the stimulator. Of those participants who used vaginal cones, one reported abdominal pain, two vaginitis, and one bleeding, and 14 reported motivation problems and trouble in using the cones.