Physician preferences for bone metastasis drug therapy in Canada

Abstract

Background: Currently in Canada, several bone-targeted agents (btas) with varying characteristics are available for the prevention of skeletal-related events (sres) in patients with bone metastasis secondary to solid tumours. In the present study, we evaluated the preferences of physicians in Canada for the various attributes of the available btas.

Methods: Physicians treating patients with bone metastasis from solid tumours were invited to complete an online discrete-choice experiment. Respondents were asked to choose between pairs of hypothetical medications for virtual patients. Each hypothetical medication was described based on predefined key attributes: time until first sre, time until worsening of pain, medication-related annual risk of osteonecrosis of the jaw (onj), medication-related annual risk of renal impairment, and mode of administration. A random-parameters logit model was used to analyze the choices between hypothetical medications and thus infer physician preferences for medication attributes.

Results: Responses from the 200 physicians who completed the discrete-choice experiment suggested that months until first sre, risk of renal impairment, and months until worsening of pain were considered the most important attributes affecting choice of bta. The annual risk of onj was considered the least important attribute.

Conclusions: When making treatment decisions about the choice of bta for patients with bone metastasis from solid tumours, delaying sres and worsening of pain, and reducing the risk of renal impairment are primary considerations for physicians in Canada.

Keywords: Bone metastases; bone-targeted agents; conjoint analysis; discrete-choice experiments; physician preferences; skeletal-related events.

FIGURE 1

Example choice question: Patient 1—A 57-year-old woman who was diagnosed with breast cancer and developed bone metastases along with 2 cm mediastinal and supraclavicular adenopathy 3 years after her initial diagnosis. She initially received TC adjuvant chemotherapy. The tumour is ER/PR positive and HER2-negative. She was on an adjuvant aromatase inhibitor at the time of her relapse. Her recurrence was noted by examination identifying the supraclavicular adenopathy. On further questioning, she admits to increasing mid-back (thoracic area) pain, which she rates as a 4 on a scale of 0 to 10. The patient’s health is otherwise good (high performance status) with no history of kidney disease and no significant comorbidities. TC = docetaxel with cyclophosphamide; ER = estrogen receptor; PR = progesterone receptor; HER2 = human epidermal growth factor receptor 2; SRE = skeletal-related event; BPI = Brief Pain Inventory; ONJ = osteonecrosis of the jaw.

FIGURE 2

Preference weights. The vertical bars surrounding each mean preference weight denote the 95% confidence interval (CI) for the point estimate; if the CIs for adjacent levels in a particular attribute do not overlap, the mean estimates for those levels are statistically different at the 5% level of significance. However, overlapping CIs do not necessarily imply a lack of statistical significance in the differences between preference weights within an attribute at the 5% level of significance. BPI = Brief Pain Inventory; ONJ = osteonecrosis of the jaw; SRE = skeletal-related event.