Background: Although societal preference weights are desirable to inform resource-allocation decision-making, patient experienced health state-based value sets can be useful for clinical decision-making, but context may matter.
Objective: To estimate EQ-5D value sets using visual analog scale (VAS) ratings for patients undergoing knee replacement surgery and compare the estimates before and after surgery.
Methods: We used the Patient Reported Outcome Measures data collected by the UK National Health Service on patients undergoing knee replacement from 2009 to 2012. Generalized least squares regression models were used to derive value sets based on the EQ-5D-3 level using a development sample before and after surgery, and model performance was examined using a validation sample.
Results: A total of 90,450 preoperative and postoperative valuations were included. For preoperative valuations, the largest decrement in VAS values was associated with the dimension of anxiety/depression, followed by self-care, mobility, usual activities, and pain/discomfort. However, pain/discomfort had a greater impact on VAS value decrement in postoperative valuations. Compared with preoperative health problems, postsurgical health problems were associated with larger value decrements, with significant differences in several levels and dimensions, including level 2 of mobility, level 2/3 of usual activities, level 3 of pain/discomfort, and level 3 of anxiety/depression. Similar results were observed across subgroups stratified by age and sex.
Conclusions: Findings suggest patient experience-based value sets are not stable (ie, context such as timing matters). However, the knowledge that lower values are assigned to health states postsurgery compared with presurgery may be useful for the patient-doctor decision-making process.