This study aimed to develop mapping algorithms from the Expanded Prostate Cancer Index Composite (EPIC) and the Short-Form (SF) Health Surveys to the Patient-Oriented Prostate Utility Scale (PORPUS), an econometric instrument specifically developed for patients with prostate cancer.
Data were drawn from 2 cohorts concurrently administering PORPUS, EPIC-50, and SF-36v2. The development cohort included patients who had received a diagnosis of localized or locally advanced prostate cancer from 2017 to 2019. The validation cohort included men who had received a diagnosis of localized prostate cancer from 2014 to 2016. Linear regression models were constructed with ln(1 - PORPUS utility) as the dependent variable and scores from the original and brief versions of the EPIC and SF as independent variables. The predictive capacity of mapping models constructed with all possible combinations of these 2 instruments was assessed through the proportion of variance explained (R2) and the agreement between predicted and observed values. Validation was based on the comparison between estimated and observed utility values in the validation cohort.
Models constructed with EPIC-50 with and without SF yielded the highest predictive capacity (R2 = 0.884, 0.871, and 0.842) in comparison with models constructed with EPIC-26 (R2 = 0.844, 0.827, and 0.776). The intraclass correlation coefficient was excellent in the 4 models (>0.9) with EPIC and SF. In the validation cohort, predicted PORPUS utilities were slightly higher than those observed, but differences were not statistically significant.
Mapping algorithms from both the original and the abbreviated versions of the EPIC and the SF Health Surveys allow estimating PORPUS utilities for economic evaluations with cost-utility analyses in patients with prostate cancer.
Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research. 2021 Sep 08 [Epub]
Víctor Zamora, Olatz Garin, Yolanda Pardo, Àngels Pont, Cristina Gutiérrez, Patricia Cabrera, Francisco Gómez-Veiga, José Ignacio Pijoan, Mark S Litwin, Montse Ferrer, Multicentric Spanish Group of Clinically Localized Prostate Cancer
Health Services Research Group, Hospital del Mar Medical Research Institute, Barcelona, Spain; Department of Paediatrics, Obstetrics and Gynaecology, and Preventive Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; CIBER en Epidemiología y Salud Pública, CIBERESP, Spain., Health Services Research Group, Hospital del Mar Medical Research Institute, Barcelona, Spain; CIBER en Epidemiología y Salud Pública, CIBERESP, Spain; Universitat Pompeu Fabra, Barcelona, Spain. Electronic address: ., Health Services Research Group, Hospital del Mar Medical Research Institute, Barcelona, Spain; Department of Psychiatry and Legal Medicine, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; CIBER en Epidemiología y Salud Pública, CIBERESP, Spain., Health Services Research Group, Hospital del Mar Medical Research Institute, Barcelona, Spain; CIBER en Epidemiología y Salud Pública, CIBERESP, Spain., Institut Català d'Oncologia, IDIBELL, L'Hospitalet de Llobregat, Spain., Department of Radiation Oncology, Hospital Universitario Virgen del Rocío, Sevilla, Spain., Complejo Hospitalario Universitario de Salamanca, Grupo de Investigación Translacional de Urología, Instituto de Investigación de Salamanca, Salamanca, Spain., CIBER en Epidemiología y Salud Pública, CIBERESP, Spain; Department of Clinical Epidemiology, Hospital Universitario de Cruces, Barakaldo, Vizcaya, Spain., Schools of Medicine, Public Health and Nursing, University of California, Los Angeles, CA, USA.