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 .
Asthma symptom utility index: reliability, validity, responsiveness, and the minimal important difference in adult asthmatic patients.
BACKGROUND The evaluation of asthma symptoms is a core outcome measure in asthma clinical research . The Asthma Symptom Utility Index ( ASUI ) was developed to assess the frequency and severity of asthma symptoms . The psychometric properties of the ASUI are not well characterized , and a minimal important difference ( MID ) is not established . OBJECTIVES We assessed the reliability , validity , and responsiveness to change of the ASUI in a population of adult asthmatic patients . We also sought to determine the MID for the ASUI . METHODS Adult asthmatic patients ( n = 1648 ) from 2 previously completed multicenter r and omized trials were included .  Demographic information , spirometric results , ASUI scores , and other asthma question naire scores  were obtained at baseline and during follow-up visits . Participants also kept a daily asthma diary . RESULTS The internal consistency reliability of the ASUI was 0.74 ( Cronbach α ) . Test-retest reliability was 0.76 ( intraclass correlation ) . Construct validity was demonstrated by significant correlations between ASUI scores and Asthma Control Question naire scores ( Spearman correlation r = -0.79 ; 95 % CI , -0.85 to -0.75 ; P < .001 ) and Mini Asthma Quality of Life Question naire scores ( r = 0.59 ; 95 % CI , 0.51 - 0.61 ; P < .001 ) . Responsiveness to change was demonstrated , with significant differences between mean changes in ASUI scores across groups of participants differing by 10 % in percent predicted FEV(1 ) ( P < .001 ) and by 0.5 points in Asthma Control Question naire scores ( P < .001 ) . Anchor-based and statistical methods support an MID for the ASUI of 0.09 points . CONCLUSIONS The ASUI is reliable , valid , and responsive to changes in asthma control over time . The MID of the ASUI ( range of scores , 0 - 1 ) is 0.09
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 .