Patient preferences for nutritional supplementation to improve fracture healing: a discrete choice experiment

Abstract

Objective: Vitamin D is often prescribed as an adjuvant therapy to aid fracture healing due to its biological role in bone health. However, the optimal frequency, dosage and duration of vitamin D supplementation for non-osteoporotic fracture healing has not been established. The objective of this study was to determine patient preferences for fracture healing relative to hypothetical vitamin D supplementation dosing options.

Design: Discrete choice experiment.

Setting: Level 1 trauma centre in Baltimore, Maryland, USA.

Participants: 199 adult (18-60 years) patients with a fracture.

Primary outcome measures: Parameter estimates of utility for fracture healing relative to dosing regimens were analysed using hierarchical Bayesian modelling.

Results: A reduced risk of reoperation (34.3%) and reduced healing time (24.4%) were the attributes of greatest relative importance. The highest mean utility estimates were for a one-time supplementation dose (ß=0.71, 95% CI 0.41 to 1.00) followed by a reduced risk of reoperation (ß=0.41 per absolute % reduction, 95% CI 0.0.36 to 0.46). Supplementation for 24 weeks in duration (ß=-0.83, 95% CI -1.00 to -0.67) and a daily supplement (ß=-0.29, 95% CI -0.47 to -0.11) had the lowest mean utilities. The 'no supplement' option had a large negative value suggesting supplementation was generally desirable in this sample population. Among other possible clinical scenarios, patients expected a 2% reduction in the absolute risk of reoperation or a 3.1-week reduction in healing time from the baseline to accept a treatment regimen requiring two separate doses of supplementation, two blood tests and a cost of $20 within 3 months of injury.

Conclusions: Patients with orthopaedic trauma demonstrated strong willingness to take a vitamin D supplement that would decrease risk of reoperation and reduce healing time. Furthermore, these findings specify the required decrease in reoperation risk and reduction in healing time patients would expect to adhere to possible vitamin D dosing regimens.

Keywords: discrete choice experiment; fracture; preferences; vitamin D.

Figure 1

Sample question from the discrete choice experiment survey administered to participants. In each question, the values for each hypothetical supplement were varied.

Figure 2

The relative importance across all attributes included in the discrete choice experiment.