Mapping FACT-P and EORTC QLQ-C30 to patient health status measured by EQ-5D in metastatic hormone-refractory prostate cancer patients.
OBJECTIVE
To construct and validate a prediction model of preference-adjusted health status (EQ-5D) for metastatic hormone-refractory prostate cancer (HRPCA) patients using cancer-specific health-related quality of life (HRQoL) measures.


METHODS
Data were obtained from a multicenter, multinational observational study of metastatic HRPCA patients conducted during 2002 to 2004. In addition to clinical and resource utilization, preference-adjusted health status (EQ-5D) and HRQoL (Functional Assessment of Cancer Therapy-Prostate [FACT-P] and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ-C30]) data were collected. Predictive validity of ordinary least square (OLS) and median regressions of various model specifications were tested using cross-validation samples. The selected specification was then further refined and tested for alternative model specifications and restrictions.


RESULTS
OLS regression with both HRQoL measures as individual components and patient demographics was the best-performing model. It explained 58.2% of the observed EQ-5D variation in the validation sample. A model including only the prostate cancer-specific HRQoL measure, FACT-P, explained 53.5% of the observed EQ-5D variation.


CONCLUSIONS
The models developed have good predictive validity. These algorithms enable researchers to translate cancer-specific HRQoL measures to preference-adjusted health status in metastatic HRPCA patients. The findings will help perform health status adjustments in cost-utility analyses.
Wu
Eric Q
EQ
Analysis Group, Inc., Boston, MA 02199, USA. ewu@analysisgroup.com
Mulani
Parvez
P
Farrell
Max H
MH
Sleep
Darryl
D
D000230:Adenocarcinoma / Q000473:pathology / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology / Q000523:psychology*; D011788:Quality of Life
D018931:Antineoplastic Agents, Hormonal