Letters

Conservative management of genuine stress incontinence in women

Study's flaws may be misleading

Authors' reply

Study's flaws may be misleading

EDITORBø et al's study comparing the various methods used in the conservative management of genuine stress incontinence has several flaws, which may mislead readers.¹ The study has been described as pragmatic, reflecting current practice. This view is undermined by the instructions to the women in the vaginal cone and electrical stimulation groups not to perform pelvic floor exercises while using their treatments; this does not reflect current clinical practice. In a prospective randomised study comparing the efficacy of pelvic floor exercises in combination with vaginal cones and pelvic floor exercises alone the combination of the two treatments was significantly more efficacious than either alone.²

In a prospective randomised study comparing the efficacy of pelvic floor exercises in combination with vaginal cones, vaginal cones alone, and vaginal electrical stimulation alone, again the combination of two techniques produced greater improvement in urinary incontinence.³

We are also concerned about the differing numbers of visits to a therapist for each group. The pelvic floor exercise group had weekly visits whereas the other groups were seen monthly. This would introduce bias; Wyman et al proposed that the specific conservative treatments are not as important as having frequent contact with the patients, with education and counselling.⁴ Thus the pelvic floor exercise group should have a better response to treatment owing to the increased time they had with a therapist.

Vik Khullar, Subspecialty trainee in urogynaecology. 
vkhullar{at}cwcom.net

Stefano Salvatore, Research fellow. 
John Bidmead, Research fellow. 
Kate Anders, Urogynaecology nurse specialist. 
Linda Cardozo, Professor of urogynaecology. 
Department of Urogynaecology, King's College Hospital, London SE5 9RS

Authors' reply

EDITORWe tried to give the best possible treatment for all groups within a pragmatic setting. Thus the electrical stimulation and vaginal cones groups had 30 and 20 minutes' training daily, respectively, whereas the exercise group had less than 8-10 minutes' training. This should favour the electrical stimulation and vaginal cones groups, and it is strange that Khullar et al do not mention this as a flaw. Another flaw that works against the exercise group is that both the vaginal cones and electrical stimulation groups had individual treatment with direct proprioception to the pelvic floor, while the exercise group was taught without proprioception.

If the women are contracting simultaneously with the current, how can we then conclude that it is the electrical stimulation and not the voluntary contraction that gives the effect? The point of this study was to evaluate the effect of electrical stimulation and cones. An interesting hypothesis is whether contraction simultaneously with electrical stimulation gives better results than contraction without. This should be investigated in a future study. Other studies have shown no significant additional effect of adding electrical stimulation to exercise.¹

Strong motivation and instruction are important factors in increasing muscle strength and part of strength training regimens. One of the benefits advocated by manufacturers of vaginal cones and electrical stimulators is that these methods can be used at home without the therapist, thus being cheaper. These methods have been used in this way in the Scandinavian countries for years. In our study all groups had the same monthly visits, for motivation, individual follow up, and contact with the therapist. The exercise group had weekly contacts in groups in addition. This may have enhanced their improvement. This is the way we teach pelvic floor muscle exercise, and it is difficult to understand how this group contact could give such huge differences in a provocation test at the office of a blinded investigator.

Khullar et al give references to their own work presented as two abstracts. As far as we can see their results are similar to our findings. In the first study exercise and vaginal cones did not give significantly different results. However, the drop out rate in the vaginal cone group was 25%, and no intention to treat analysis was performed. In the second study, adding pelvic floor muscle exercise to treatment with vaginal cones was more effective than treatment with vaginal cones alone.

Kari Bø, Exercise scientist. 
karib{at}brage.idrettshs.no

Ingar Holme, Professor. 
Norwegian Centre for Physiotherapy Research and Norwegian University of Sport and Physical Education, PO Box 4014, Ullevål Stadion, 0806 Oslo, Norway

Trygve Talseth, Consultant urologist. 
National Hospital of Norway, Oslo