Validity and reliability of patient selected goals as an outcome measure in overactive bladder

The purpose of this study is to assess the validity of patient goal achievement in overactive bladder (OAB).

Data were taken from a placebo-controlled randomised trial of transdermal oxybutynin and open label extension study. Face validity was assessed using qualitative analysis. Convergent validity was assessed by comparison with objective symptom improvement. Responsiveness was assessed at 4 s, using the standardised effect size. Reliability was assessed between 4 and 12 weeks of treatment.

Ninety-six women were randomised. There were moderate correlations (0.50-0.51) between goal achievement and symptom improvement for urinary urgency and urge incontinence. Mean goal achievement demonstrated good reliability (intraclass correlation = 0.82) but low responsiveness (r = 0.14) between transdermal oxybutynin and placebo-treated groups.

Although patient goals have good face validity and can be reliably measured, they have limited convergence with conventional measures of OAB severity and improvement and low responsiveness.