Participants

6.5.1 Inclusion and exclusion criteria.

Women with SUI symptoms (with or without additional urgency or urge

incontinence symptoms), as established through clinical history taking, were

recruited. This study seeks to establish whether routine use of biofeedback

has benefit for women who can already contract their muscles. Therefore

only women able to contract their pelvic floor muscles were eligible for

recruitment. Women who were referred to the continence physiotherapy clinic

at Tameside NHS Foundation Trust between December 2008 and February

2010 were recruited. The service accepts patients referred by a GP,

gynaecologist, urologist, the Continence Advisory Service (CAS) or other

health care professional.

The exclusion criteria ensured that results could be attributable to the

treatments used and not to extraneous factors, and also to comply with the

ethics of conducting research. They were kept to a minimum in order to

Exclusion criteria were:

• Women unable to give informed consent.

• Women with limited English language skills who were unable to complete the questionnaires, as no resources were available to enable

translators or interpreters to be used.

• Women with insufficient cognitive or communication skills to complete the questionnaires, as assessed by the clinical team.

• Women with urgency or urge incontinence as their predominant complaint, as, although, women often present with mixed symptoms,

the study primarily evaluated the intervention for women with SUI. • Women with a fluctuating condition likely to affect their continence such

as Multiple Sclerosis.

• Women who were unable to attend clinic, as the intervention was clinic- based.

• Women who could not tolerate use of an internal vaginal sensor probe as this was the method by which sEMG biofeedback was given.

• Women who, on vaginal examination, had no pelvic floor muscle contraction, as this study sought to establish whether biofeedback adds

benefit for women who can already contract their pelvic floor muscles.

6.5.2 Ethical Considerations

All necessary ethical and R&D approvals including permissions from the

University of Salford and Tameside NHS Trust R&D committee were obtained

before the study started. Local chaperoning and infection control policies were

adhered to. Ethical consideration was given to the information available to

questionnaires used in the study, depriving the Control group of access to

biofeedback treatment (for the study duration) and the acceptability and

invasive nature of using an internal probe for biofeedback in the Intervention

group. The study’s focus was whether routine use of biofeedback added

benefit for women who could already perceive a pelvic floor muscle

contraction. sEMG biofeedback is already a recommended treatment option

for women unable to perceive a pelvic floor muscle contraction. Including

these women would risk them being allocated to the control group, resulting in

a delay to treatment which was considered unethical by the researcher, as the

biofeedback equipment was usually available for these women in this clinic.

Neuromuscular electrical stimulation would be the treatment option of choice

for women with no identifiable contraction on clinical examination (Laycock et

al., 2001b).

Discussion with the women ensured they were fully informed of all aspects of

the study, potential risks and benefits. They were given written information in

the form of a patient information leaflet, and contact details of independent

information sources should they needed further advice. The questionnaires

were brief, requiring just a few minutes to complete. The principles of

informed consent, data protection and anonymity were adhered to. Women

were informed they could leave the study at any time and that their care would

not be adversely affected by their decision. They were also made aware that

the purpose of the research study was to generate new knowledge about the

benefits of existing treatments, which are in common use. The researcher

was trained in good practice in research and undergone research ethics

receive sEMG biofeedback following discussion with the

physiotherapist/researcher.

6.5.3 Power calculation and sample size

Normative data from the author of the primary outcome measure (personal

communication, Chen 2007), and scores from the women who piloted the

questionnaire prior to the main study, were used to calculate the effect size.

This information estimated that a 10 point difference between groups on the

pelvic floor muscle exercise self-efficacy scale (17 minimum and 85 maximum

possible score) would be considered a clinically significant effect. Power and

sample size were calculated using data from Chen (2004) and based on

normality. This indicated that 25 patients per group would be needed to

detect a clinically important difference of 10 points at the 5% significance level

with 80% power, and assuming a control mean (standard deviation) of 64

(14). To allow for drop-out, a final sample of 60 was identified. It was

expected that three new participants could be recruited each week, meaning

recruitment would take 25 weeks and recruitment and delivery of the

intervention would be completed within 12 months.

6.5.4 Recruitment process and randomisation

Women attending for their first physiotherapy appointment were seen by the

researcher/physiotherapist. Those fulfilling the inclusion and exclusion criteria

had the study explained to them and if they were interested in participating

were given a written information leaflet and consent form (Appendices 5 and

6). A further appointment was given for two weeks time, along with a phone

needed. At the second visit there was further opportunity to ask questions and

discuss any issues. If women agreed to participate, consent was obtained. A

copy of the consent form was given to the participant and a copy was also

attached to the patient record, after which baseline assessment

questionnaires were completed and participants were randomised into either

the intervention or control group.

To ensure adequate concealment of allocation, the participants were not

randomised until after the baseline assessments had been completed.

Randomisation was blinded. An independent statistician undertook this

process and produced serially numbered, sealed opaque envelopes from the

randomisation schedule, which was produced using a specially designed

computer package (Stata version 8) incorporating randomly varying block

sizes to prevent block size determination. After baseline tests were

completed, the researcher opened the next numbered envelope to find out the

allocated group for each participant. Due to the nature of the intervention it

was not possible to blind the physiotherapist or the patient to the treatment

received, however the data analysis was checked by staff blind to group

identity.