EuroQol EQ-5D and condition-specific measures of health outcome in women with urinary incontinence: reliability, validity and responsiveness.
OBJECTIVE
To evaluate the measurement properties of the EuroQoL EQ-5D and two condition-specific patient-reported outcome measures--the Symptom Severity Index (SSI) and the Urinary Incontinence-Specific Quality of Life instrument (I-QoL)--in women with urinary incontinence.


METHODS
A questionnaire comprising all instruments was completed by women taking part in a clinical trial of physiotherapy for urinary incontinence. Follow-up questionnaires were at 6 weeks and 5 months. Data quality, internal consistency reliability, validity and responsiveness were assessed.


RESULTS
One hundred and seventy-four patients taking part in the clinical trial completed the questionnaire. Instruments had low levels of missing data. The EQ-5D had a large ceiling effect and poor responsiveness. The SSI had poor validity and responsiveness. The I-QoL had levels of reliability that supported application in group assessment, and in some cases, individual assessment, and good evidence of validity. The I-QoL was the most responsive instrument at both 6 weeks and 5 months.


CONCLUSIONS
The I-QoL was the best performing instrument and is recommended as a continence-specific measure of quality of life in a clinical trial setting. The SSI and EQ-5D are not recommended. Alternative generic instruments, which support economic evaluation, require further evaluation in trials of female urinary incontinence.
Haywood
Kirstie L
KL
Royal College of Nursing Research Institute, School of Health and Social Studies, Warwick University, Coventry CV4 5AL, UK. kirstie.haywood@rcn.org.uk
Garratt
Andrew M
AM
Lall
Ranjit
R
Smith
Jan Fereday
JF
Lamb
Sarah E
SE
D005260:Female; D006304:Health Status; D006305:Health Status Indicators; D006801:Humans; D008875:Middle Aged; D011581:Psychological Tests; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014549:Urinary Incontinence / Q000523:psychology* / Q000628:therapy