Conclusion Various methods have been used at all stages of CSPBM development .
The choice between developing a classification system de novo or from an existing instrument may depend on the availability of a suitable existing measure , while the choice between a decomposed or composite approach appears to be determined primarily by the purpose for which the instrument is design ed .
Background Health state utility values ( HSUVs ) are required to calculate quality -adjusted life-years ( QALYs ) .
They are frequently derived from generic preference-based measures of health .
However , such generic measures may not capture health attributes of relevance to specific conditions .
In such cases , a condition-specific preference-based measure ( CSPBM ) may be more appropriate .
Objective This systematic review aim ed to identify all published accounts of developing CSPBMs to describe and appraise the methods used .
Development of the EXACT-U: a preference-based measure to report COPD exacerbation utilities.
BACKGROUND The exacerbations of chronic obstructive pulmonary disease tool ( EXACT ) is a condition-specific daily diary recently developed to evaluate the frequency , severity , and duration of chronic obstructive pulmonary disease ( COPD ) exacerbations . A preference-based algorithm for the EXACT would allow utilities to be reported from patients during an exacerbation when EQ-5D data are not available . OBJECTIVE To develop the exacerbations of chronic obstructive pulmonary disease tool-utility ( EXACT-U ) , a condition-specific preference-based measure to report utilities from the EXACT for use in cost-effectiveness studies . METHODS Five items with three to five levels comprise the EXACT-U. Two groups of health states and respondents were constructed to allow for model development ( Development group ) and predictive validity testing ( Validation group ) using independent sample s. Members of the UK general public each valued 11 r and omized health states using time trade-offs ( TTOs ) scaled from full health/dead with 10-year duration s. Regression models estimated from the Development group using individual data , mean data , and panel design s. Models assessed by number of inconsistent coefficients estimated and R(2 ) and tested against observed utilities from the Validation group using mean absolute error ( MAE ) and root mean squared error ( RMSE ) . RESULTS A total of 55 health states , including the best and worst states , were valued in TTO interviews conducted with 400 respondents . Ten models were developed . The final preferred model contained no logical inconsistencies and found MAE = 0.04 and RMSE = 0.05 with a predicted utility range from 0.09 to 0.95 . CONCLUSIONS The EXACT-U is a condition-specific preference-based measure with strong predictive validity to report daily utilities during an exacerbation
Conclusion Various methods have been used at all stages of CSPBM development .
The choice between developing a classification system de novo or from an existing instrument may depend on the availability of a suitable existing measure , while the choice between a decomposed or composite approach appears to be determined primarily by the purpose for which the instrument is design ed .
Background Health state utility values ( HSUVs ) are required to calculate quality -adjusted life-years ( QALYs ) .
They are frequently derived from generic preference-based measures of health .
However , such generic measures may not capture health attributes of relevance to specific conditions .
In such cases , a condition-specific preference-based measure ( CSPBM ) may be more appropriate .
Objective This systematic review aim ed to identify all published accounts of developing CSPBMs to describe and appraise the methods used .