Comparison of the Psychometric Performance of a New Condition-Specific Preference-Based Measure Derived from the Cfq-R (CFQ-R-8D) to EQ-5D-3L and SF-6D to Evaluate Health-Related Quality-of Life (HRQOL) in People with Cystic Fibrosis (CF)
Author(s)
Mukuria C*1;Rowen D1;Brazier JE1;McGarry L2;Quittner A3;Lou Y2;Sosnay P2, Acaster S4
1University of Sheffield, Sheffield, UK, 2Vertex Pharmaceuticals Incorporated, Boston, MA, USA, 3Behavioral Health Systems Research, Miami, FL, USA, 4Acaster-Lloyd Consulting Ltd, London, UK
OBJECTIVES: CF is a multi-systemic chronic disease affecting HRQoL. Generic preference-based measures of health such as EQ-5D and SF-6D are typically used to estimate utilities for cost effectiveness analysis. However, evidence suggests EQ-5D is not sensitive to meaningful differences in lung function and HRQoL amongst people with CF. Here we compare the psychometric performance of EQ-5D-3L and SF-6D to CFQ-R-8D, a new CF-specific preference-based measure developed from the CFQ-R.
METHODS: Data from three clinical trials (NCT01807923, NCT01807949, NCT02347657) of people with CF were used to assess known-groups validity by severity group based on lung function (ppFEV1) and pulmonary exacerbations, responsiveness to change over time, convergent validity, and differences in utilities generated by EQ-5D-3L (n=997 at baseline), SF-6D (n=441 at baseline), and CFQ-R-8D (n=1438 at baseline).
RESULTS: All measures showed evidence of known-groups validity (p values <0.05), with highest effect sizes (ES) for CFQ-R-8D. For responsiveness, the SF-6D had the largest mean change over time and largest ES, followed by CFQ-R-8D and then EQ-5D-3L. For convergent validity, CFQ-R-8D utilities were strongly correlated with EQ-5D-3L and SF-6D utilities (r values >0.5), and across the measures, dimensions capturing similar concepts were predominantly strongly or moderately correlated (r values >0.3). CFQ-R-8D and SF-6D showed better ability to detect change than EQ-5D-3L: both showed < 9% responses in full health (ceiling effects) vs 61% - 62% for EQ-5D-3L. Notably, among individuals classified as being full health (utility = 1) by EQ-5D-3L and SF-6D, CFQ-R-8D captured CF-specific health problems, particularly coughing, abdominal pain, and breathing difficulty, undetected by the generic measures (CFQ-R-8D range = 0.401-1).
CONCLUSIONS: In people with CF, CFQ-R-8D shows stronger evidence of good psychometric performance than EQ-5D, and similar evidence to SF-6D. CFQ-R-8D captures more condition-specific symptoms than EQ-5D or SF-6D, which are important determinants of HRQoL for people with CF.
METHODS: Data from three clinical trials (NCT01807923, NCT01807949, NCT02347657) of people with CF were used to assess known-groups validity by severity group based on lung function (ppFEV1) and pulmonary exacerbations, responsiveness to change over time, convergent validity, and differences in utilities generated by EQ-5D-3L (n=997 at baseline), SF-6D (n=441 at baseline), and CFQ-R-8D (n=1438 at baseline).
RESULTS: All measures showed evidence of known-groups validity (p values <0.05), with highest effect sizes (ES) for CFQ-R-8D. For responsiveness, the SF-6D had the largest mean change over time and largest ES, followed by CFQ-R-8D and then EQ-5D-3L. For convergent validity, CFQ-R-8D utilities were strongly correlated with EQ-5D-3L and SF-6D utilities (r values >0.5), and across the measures, dimensions capturing similar concepts were predominantly strongly or moderately correlated (r values >0.3). CFQ-R-8D and SF-6D showed better ability to detect change than EQ-5D-3L: both showed < 9% responses in full health (ceiling effects) vs 61% - 62% for EQ-5D-3L. Notably, among individuals classified as being full health (utility = 1) by EQ-5D-3L and SF-6D, CFQ-R-8D captured CF-specific health problems, particularly coughing, abdominal pain, and breathing difficulty, undetected by the generic measures (CFQ-R-8D range = 0.401-1).
CONCLUSIONS: In people with CF, CFQ-R-8D shows stronger evidence of good psychometric performance than EQ-5D, and similar evidence to SF-6D. CFQ-R-8D captures more condition-specific symptoms than EQ-5D or SF-6D, which are important determinants of HRQoL for people with CF.
Conference/Value in Health Info
2020-11, ISPOR Europe 2020, Milan, Italy
Value in Health, Volume 23, Issue S2 (December 2020)
Code
PR1
Topic
Study Approaches
Topic Subcategory
Clinical Trials
Disease
Respiratory-Related Disorders