Outcome measures

6 7.1 Self-efficacy

Measured using the PFME self-efficacy scale (Chen, 2004) detailed in

Appendix 10.

The pelvic floor muscle exercise self-efficacy questionnaire is a 17 item scale,

each with a 5-point Likert type scale. Each item is a statement about different

aspects of pelvic floor muscle exercise self-efficacy, for example belief in

ability to perform the exercises correctly, overcome barriers, belief that the

exercises will provide benefit. Each statement starts ‘I believe ….: and asks

for a response category box 1-5 to be marked with a cross, for each

statement. 1=not very confident to 5=extremely confident. The maximum

score possible for the scale is 85 and the minimum is 17. High scores show

high levels of pelvic floor muscle exercise self-efficacy.

The Chen PFME self-efficacy scale (Chen, 2004) was developed and

validated in Taiwan on 106 women with urinary incontinence. Exploratory

factor analysis identified two factors explaining 66.71% of the total variance.

Construct validity was established through examining the concurrent validity

against 3 other scales: the general self-efficacy scale (GSE) (Schwarzer,

1993), the incontinence impact questionnaire-7 (IIQ-7) (Shumaker et al.,

1994) and a two item perceived PFME benefits scale (developed for the

validation study). The scale shows high internal consistency (Cronbach’s

alpha of 0.95) and good test-retest reliability (over 6-30 days, r=0.86,

p<0.001). This indicates good stability. Responsiveness was not evaluated in

the validation study. To help establish whether the scale was able to be used

with patients who met the inclusion criteria during the preparation stage of the

study and consultees were asked whether the items could be easily

understood. As a result of patient feedback, an adjustment was made,

without changing the meaning, to the wording of an item (see Appendix 11 for

wording before and after this adjustment).

6.7.2 PFME Adherence

Adherence to PFME was measured using patient-reported recall of adherence

behaviour from the previous day and the previous seven days (Alewijnse et

al., 2003 Appendix 12). One week was chosen as a period likely to reflect

fluctuation in exercise behaviour, but not too long in order to ensure accurate

recall. It is short and user-friendly and comprises six items which attempt

succinctly to capture actual exercise behaviour and self-evaluated success

(on a scale of 0 to 10). Whether the exercises had been remembered and

understood was evaluated using a 7-point Likert scale (+3 to -3) as well as the

number of days the exercises were performed, how many times a day and the

reasons for non-adherence. Understanding and recall of the exercises was

assessed by asking participants to provide a written description of the

exercises they performed. Completion in the clinic waiting area prior to

treatment reduced the likelihood of forgetting the diary, impact of social

desirability, and ensured that participants had time to concentrate on

completing them accurately (Hay-Smith 2007, personal correspondence).

6.7.3 Depression

The Hospital Anxiety and Depression Scale (HAD) (Zigmond & Snaith, 1983

information presented for each group at baseline. This is because depression

levels are thought to influence PFME self-efficacy (Broome, 2003). It is a

commonly used 14-item ordinal scale used to detect anxiety and depression

independent of somatic symptoms. It consists of 2 sub-scales (7 items in

each) measuring anxiety and depression. A 4-point response scale from 0

(absence of symptoms) to 3 (maximum symptoms) is used. Possible scores

for each sub-scale range from 0 to 21. Higher scores indicate greater levels of

anxiety or depression.

6.7.4 Symptom Severity

The International Consultation on Incontinence questionnaire or ICIQ-UI SF

(Avery et al, 2004) is a participant-completed questionnaire which provides a

quick and simple measure of the severity and impact of urinary incontinence

on the individual (see Appendix 14). It demonstrates high reliability, validity

and responsiveness to change, and, has good correlation with other more

cumbersome objective measures such as the pad test (Karantanis et al.,

2004) and urodynamics findings (Seckiner et al., 2007). As a result, it is

widely used internationally. It comprises 4 items, three of which (frequency of

leakage, amount of leakage and interference with everyday life) are

summated to give a single score. The fourth item diagnoses the participants’

perceived causes of the incontinence. The score range is 0 to 21, high scores

6.7.5 Pelvic floor muscle strength

The modified oxford scale (MOS) (Messelink et al., 2005) evaluates strength

of the pelvic floor muscles assessed by vaginal examination at week 0 and

week 12. The 6-point ordinal scale (0-5 described in Figure 11) is easy to

perform and also establishes whether a correct muscle contraction and ‘lift’ is

occurring (which is an important part of the treatment process). The MOS

shows inter-rater reliability (Bø, 2001) but greater reliability if performed by a

single assessor (Laycock et al., 2001b).

0 No contraction 1 Flicker of a contraction 2 Weak contraction

3 Moderate contraction (with lift) 4 Strong contraction (with lift) 5 Very strong contraction (with lift)

Messelink et al., 2005

Figure 11 Modified Oxford Scale to measure strength of the pelvic floor muscles

6.7.6 About data collection

All questionnaires were completed at clinic attendance to maximise return

rates. They were self-completed in privacy in the waiting area, sealed into

envelopes and returned to the clinic receptionist before having contact with

the researcher and starting the treatment session. They were coded and

anonymous to encourage the provision of accurate information. Completed

physiotherapist/researcher had no knowledge of the questionnaire responses

while the participant was undergoing treatment.