Estimating a preference-based single index from the Overactive Bladder Questionnaire.
OBJECTIVE
The aim of the study is to estimate a preference-based single index for calculating quality-adjusted life years for patients with overactive bladder (OAB), based on a survey of the UK general population using the 5-dimensional health classification system OAB-5D, derived from the validated Overactive Bladder Questionnaire (OAB-q).


METHODS
An interview valuation survey of members of public in the South Yorkshire, UK was undertaken using the time-trade-off method. Each respondent was randomly allocated to one of 14 blocks, and valued seven states each plus the "pits" state, so that a total of 99 states were valued. A number of multivariate regression models were estimated for predicting a total of 3125 health state values defined by the classification. Models were compared and selected using a set of criteria, including overall diagnosis by adjusted R-squared, the sign and significance of individual parameter estimates, the relative size of coefficients within a given dimension and predictive ability.


RESULTS
The mean model was recommended for use in economic evaluation.


CONCLUSIONS
This will permit the cost-effectiveness of new interventions to be assessed in patients with OAB using existing and future OAB-q data sets.
Yang
Yaling
Y
School of Health and Related Research, The University of Sheffield, Sheffield, England, UK. cmp04yy@sheffield.ac.uk
Brazier
John
J
Tsuchiya
Aki
A
Coyne
Karin
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006304:Health Status; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D018803:Models, Economic; D057240:Patient Preference / Q000191:economics*; D019057:Quality-Adjusted Life Years; D006113:United Kingdom; D053201:Urinary Bladder, Overactive / Q000191:economics*; D055815:Young Adult