Patient Preferences: Results of a German Adaptive Choice-Based Conjoint Analysis (Market Research Study Sponsored by Eli Lilly and Company) in Patients on Palliative Treatment for Advanced Breast Cancer

Abstract

Introduction: Integration of patient preferences into shared decision making improves disease-related outcomes, but such data from patients with advanced breast cancer (aBC) are limited. The objective of this study was to demonstrate the relative importance of overall survival (OS) and progression-free survival (PFS) in relation to quality of life (QoL) and therapy-associated side effects from the perspective of patients with aBC.

Methods: Postmenopausal patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative aBC receiving first- or second-line treatment were recruited throughout Germany. Patient-relevant attributes for aBC therapy assessment were collected using a stepwise multimodal approach. A conjoint matrix was developed, resulting in 2 attributes for therapy goals (OS and PFS), 4 for QoL, and 6 for side effects. An online quantitative survey was then performed using adaptive choice-based conjoint (ACBC) methodology.

Results: The quantitative survey included 104 patients: 67 (64.4%) receiving first-line treatment and 37 (35.6%) receiving second-line treatment. The QoL attribute "physical agility and mobility" received the highest utility score (19.4 of 100%), reflecting the greatest importance to patients, followed by treatment goals (OS [15.2%] and PFS [14.4%]). Therapy-related side effects were less important, with nausea/vomiting being the most important (9.3%), followed by infection (6.4%) and hair loss (5.0%). The McFadden pseudo R² (0.805), the root likelihood (0.864), and the χ² test (2,809.041; p < 0.0001) indicated a very good fit of the statistical model.

Conclusion: Using ACBC analysis, it appears that QoL, OS, and PFS are most important to postmenopausal patients with aBC in relation to cancer treatment. Side effects seem to be less important if OS or PFS are prolonged and the QoL is maintained. Thus, QoL, OS, and PFS should be considered equally when making treatment decisions in aBC.

Keywords: Advanced breast cancer; Conjoint analysis; Patient preferences; Survival; Treatment.

Fig. 1

Study design. aBC, advanced breast cancer (includes locally advanced and metastatic breast cancer); ACBC, adaptive choice-based conjoint.

Fig. 2

Final conjoint matrix. act., activities; PFS, progression-free survival; OS, overall survival.

Fig. 3

Overview of the ACBC analysis results. Total: n = 104 (first-line therapy, n = 67; second-line therapy n = 37). ¹ Dimension “quality of life.” ² Dimension “therapy goals.” ³ Dimension “side effects.” * Significant difference between first- and second-line therapy (p < 0.05). ACBC, adaptive choice-based conjoint; OS, overall survival; PFS, progression-free survival.

Fig. 4

Side effects that patients most frequently wished to avoid (total and by therapy line). Total: n = 104 (first-line therapy, n = 67; second-line therapy, n = 37); patients chose 3 of 6 listed side effects that they would like to avoid if they had the choice between different treatment options.