The effect of information on preferences for treatments of metastatic renal cell carcinoma

Abstract

Objective: Limited information exists regarding the effect of uncertainty in outcomes on patient preferences for metastatic renal cell carcinoma (mRCC) treatments. This study tested the effect on patients’ preferences and willingness to tolerate toxicities when patients were provided with information about possible correlations between treatment-related toxicities and efficacy.

Research design and methods: Patients with self-reported RCC diagnosis completed an online survey. Respondents were randomly assigned to the information treatment (i.e. information about the possible correlation). Medicines were defined by progression-free survival (PFS), three toxicities potentially correlated with PFS, and one toxicity uncorrelated with PFS. Direct-elicitation questions measured willingness to tolerate the toxicities, preferences for medicines with higher toxicity but a higher chance of longer PFS, and preferences for medicines with higher toxicity during treatment and a 2 week dosing schedule break. A discrete-choice experiment (DCE) tested the effect of information on relative preferences for medication attributes.

Results: A total of 378 RCC patients completed the survey. Respondents who received the information reported greater willingness to accept more severe toxicities and preferred treatment with a higher chance of longer PFS but more severe toxicities. The DCE results were consistent with the hypothesis that the information increased willingness to tolerate toxicities; however, the results were only statistically significant for changes in fatigue (none to severe; p < 0.05) and hypertension (none to manageable; p < 0.05).

Limitations: Online recruitment through patient support groups may limit generalizability to the population of patients with mRCC who would be candidates for the targeted therapies.

Conclusions: The findings suggest that RCC patients have diverse preferences but may be willing to continue targeted therapies, even in the presence of severe toxicities, if there is a chance of improved clinical benefit. Physicians should provide patients with comprehensive information about medication features, including toxicities and efficacy (and their potential correlation), to improve compliance and optimize outcomes.

Keywords:

• Conjoint analysis
• Patient preference
• Renal cell carcinoma
• Uncertainty

Transparency

Declaration of funding

This study was sponsored by Pfizer Inc.

Declaration of financial/other relationships

C.M. and A.B.H. have disclosed that they are full-time employees of RTI Health Solutions and were paid contractors of Pfizer in the development of the survey, the analysis and interpretation of the data, and writing this manuscript. S.S. has disclosed that she/he was paid by Pfizer for advisory boards and received research funding. C.C., S.H., E.M., and R.S. have disclosed that they are full-time employees of Pfizer and hold Pfizer stock.

CMRO peer reviewer 1 has received an honorarium from CMRO for his statistical review, but has no other relevant financial relationships to disclose. Peer reviewers 2, 3, and 4 have no relevant financial or other relationships to disclose.

Acknowledgments

We thank the Kidney Cancer Association and Kidney Cancer Canada for their assistance in recruiting patients for the survey. We also thank Amy Pugh, formerly of RTI Health Solutions (Research Triangle Park, NC, USA), for her contributions to the development of the survey and the subsequent analysis, and Juan Marcos Gonzalez and Josh Posner of RTI Health Solutions for their assistance with the analysis. Medical writing support was provided by Andy Gannon at Acumed, an Ashfield company, part of UDG Healthcare plc (New York, NY, USA), with funding from Pfizer Inc. Medical writing support with response to reviewer comments was provided by Vardit Dror PhD of Engage Scientific Solutions and funded by Pfizer Inc.

Previous presentation

Srinivas S, Mansfield C, Sandin R, et al. Exploring the effect of medication features in renal cell carcinoma: a patient preference study. Poster presented at the American Society of Clinical Oncology Genitourinary Cancers Symposium, Orlando, FL, USA, 26–28 February 2015.