There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options .
Negative changes were not associated with larger ESs .
Population -based estimation procedures and brief follow-up were associated with smaller ESs , and acute conditions with larger ESs .
Background .
A number of studies have computed the minimally important difference ( MID ) for health-related quality of life instruments .
To determine whether there is consistency in the magnitude of MID estimates from different instruments .
Quality of life of women with urinary incontinence: further development of the incontinence quality of life instrument (I-QOL)
OBJECTIVES To report on the further development of the Incontinence Quality of  Life Instrument ( I-QOL ) , a self-report quality of life measure specific to urinary incontinence ( UI ) , including its measurement model , responsiveness , and effect size . METHODS Incontinent female patients ( 141 with stress , 147 with mixed UI ) completed the I-QOL and comparative measures at screening , pretreatment , and four subsequent follow-up visits during participation in a multicenter , double-blind , placebo-controlled , r and omized trial assessing the efficacy of duloxetine . Psychometric testing followed st and ardized procedures . RESULTS Factor analysis confirmed an overall score and three subscale scores ( avoidance and limiting behaviors , psychosocial impacts , and social embarrassment ) . All scores were internally consistent ( alpha = 0.87 to 0.93 ) and reproducible ( ICC = 0.87 to 0.91 ) . The pattern of previously reported correlations with the Short-Form 36-item Health Survey and Psychological Well-Being Schedule were confirmed . Responsiveness statistics using changes in the independent measures of stress test pad weight , number of incontinent episodes , and patient global impression of improvement ranged from 0.4 to 0.8 . Minimally important changes ranged from 2 % to 5 % in association with these measures and effect sizes . CONCLUSIONS In a clinical trial , the I-QOL proved to be valid , reproducible , and responsive to treatment for UI in women
There was no consistent relationship with factors such as disease-specific or generic instrument or the number of response options .
Negative changes were not associated with larger ESs .
Population -based estimation procedures and brief follow-up were associated with smaller ESs , and acute conditions with larger ESs .
Background .
A number of studies have computed the minimally important difference ( MID ) for health-related quality of life instruments .
To determine whether there is consistency in the magnitude of MID estimates from different instruments .