Mapping expanded prostate cancer index composite to EQ5D utilities to inform economic evaluations in prostate cancer: Secondary analysis of NRG/RTOG 0415.

PURPOSE: The Expanded Prostate Cancer Index Composite (EPIC) is the most commonly used patient reported outcome (PRO) tool in prostate cancer (PC) clinical trials, but health utilities associated with the different health states assessed with this tool are unknown, limiting our ability to perform cost-utility analyses. This study aimed to map EPIC tool to EuroQoL-5D-3L (EQ5D) to generate EQ5D health utilities. METHODS AND MATERIALS: This is a secondary analysis of a prospective, randomized non-inferiority clinical trial, conducted between 04/2006 and 12/2009 at cancer centers across the United States, Canada, and Switzerland. Eligible patients included men >18 years with a known diagnosis of low-risk PC. Patient HRQoL data were collected using EPIC and health utilities were obtained using EQ5D. Data were divided into an estimation sample (n = 765, 70%) and a validation sample (n = 327, 30%). The mapping algorithms that capture the relationship between the instruments were estimated using ordinary least squares (OLS), Tobit, and two-part models. Five-fold cross-validation (in-sample) was used to compare the predictive performance of the estimated models. Final models were selected based on root mean square error (RMSE). RESULTS: A total of 565 patients in the estimation sample had complete information on both EPIC and EQ5D questionnaires at baseline. Mean observed EQ5D utility was 0.90±0.13 (range: 0.28-1) with 55% of patients in full health. OLS models outperformed their counterpart Tobit and two-part models for all pre-determined model specifications. The best model fit was: "EQ5D utility = 0.248541 + 0.000748*(Urinary Function) + 0.001134*(Urinary Bother) + 0.000968*(Hormonal Function) + 0.004404*(Hormonal Bother)- 0.376487*(Zubrod) + 0.003562*(Urinary Function*Zubrod)"; RMSE was 0.10462. CONCLUSIONS: This is the first study to identify a comprehensive set of mapping algorithms to generate EQ5D utilities from EPIC domain/ sub-domain scores. The study results will help estimate quality-adjusted life-years in PC economic evaluations.

The impact of concurrent granulocyte-macrophage colony-stimulating factor on quality of life in head and neck cancer patients: results of the randomized, placebo-controlled Radiation Therapy Oncology Group 9901 trial.

PURPOSE: The Radiation Therapy Oncology Group (RTOG) conducted a randomized, placebo-controlled trial evaluating the efficacy of GM-CSF in reducing mucosal injury and symptom burden from curative radiotherapy for head and neck (H&N) cancer. METHODS: Eligible patients with H&N cancer receiving radiation encompassing ≥50 % of the oral cavity or oropharynx received subcutaneous GM-CSF or placebo. Quality of life (QoL) was assessed using the RTOG-modified University of Washington H&N Symptom Questionnaire at baseline 4, 13, 26, and 48 weeks from radiation initiation. RESULTS: Of 125 eligible patients, 114 were evaluable for QoL (58 GM-CSF, 56 placebo). Patient demographics, clinical characteristics, and baseline symptom scores were well balanced between the treatment arms. At the end of the acute period (13 weeks), patients in both arms reported negative change in total symptom score indicating increase in symptom burden relative to baseline (mean -18.4 GM-CSF, -20.8 placebo). There was no difference in change in total symptom score (p > 0.05) or change in mucous, pain, eating, or activity domain scores (p > 0.01) between patients in the GM-CSF and placebo arms. Analysis limited to patients treated per protocol or with an acceptable protocol deviation also found no difference in change in total symptom score (p > 0.05) or change in domain scores (p > 0.01) between treatment arms. Provider assessment of acute mucositis during treatment did not correlate with patient-reported mucous domain and total symptom scores (p > 0.05). CONCLUSION: GM-CSF administered concurrently during head and neck radiation does not appear to significantly improve patient-reported QoL symptom burden.