Evaluating patients' preferences for multiple myeloma therapy, a Discrete-Choice-Experiment.

Abstract

Background: While there is an increasing emphasis on patient empowerment and shared decision making, patients' preferences for attributes associated with their treatment still need to be measured and considered. In the present study, patients' preferences regarding treatment of multiple myeloma (MM) were explored using direct assessment and a Discrete-Choice-Experiment (DCE).

Patients and methods: After reviewing the literature about preferences of myeloma patients we conducted a qualitative study with three focus groups consisting of six to eight MM-patients each. In order to achieve content validity, we aimed at collecting all relevant factors for an ideal MM-treatment. In a subsequent quantitative study phase, data was collected in an online or paper-pencil self-completed questionnaire. It included sociodemographic data, self-rated health (SF12v2 variation) and patients preferences of therapy characteristics using direct measurement (16 items on a five-point Likert-scale) as well as a Discrete-Choice-Experiment (DCE, eight pairs with eight characteristics).

Results: 282 patients answered the questionnaire; 46% female, age: mean 62 yrs (SD=10 years), duration of MM: 5 yrs (SD=3.8 years). Direct measurement showed effectiveness aspects (i.e. high effectiveness, long lasting effects, max. prolonged life expectancy) and further treatment options in the first places, followed by maximal prolonged life expectancy, minor side effects and therapy-free-intervals. In the DCE, alternatives with further treatment options, longer life expectancy, "not always think of the disease" and therapy-free-intervals were more likely to be chosen, giving thus similar results.

Conclusion: Besides prolongation of life expectancy and effectiveness of treatment, further treatment options are of foremost importance to multiple myeloma patients. In addition, therapy-free intervals as well as an improved emotional quality of life ("Not always think of the disease") are valued as very important. The combination of direct assessment of importance and DCE is a valid combined survey technique for eliciting preferences of patients with multiple myeloma. The former ensures content validity (the possibility to measure a longer list of potentially important aspects), the latter has the advantage to combine positive and negative therapy characteristics and to avoid the problem of ceiling effects and "all-is-important" results.