Validity of standard gamble utilities in patients referred for aortic valve replacement

Purpose: Standard gamble (SG) is the preferred method of assessing preferences in situations with uncertainty and risk, which makes it relevant to patients considered for aortic valve replacement (AVR). The present study assesses SG preferences in patients with severe aortic stenosis (AS).

Methods: All patients >18 years old with severe AS referred for AVR to our institution were invited to enroll in the study. The SG was administered by a clinical research nurse. The SF-36, EQ-5D 3L, Hospital Anxiety and Depression Scale (HADS), and AS symptoms were administered by self-completed questionnaire. We hypothesized that SG utilities would have low-to-moderate correlations with physical and mental aspects of health based on our pathophysiological understanding of severe AS. No correlations were expected with echocardiographic measures of the aortic valve.

Results: The response rate for SG was 98 %. SG moderately correlated with physical aspects of SF-36 (PCS, role-physical, vitality), health transition, AS symptoms, and EQ-VAS (ρ S = 0.31-0.39, p < 0.001) and had low correlation with mental aspects of SF-36 and EQ-5D (ρ S = 0.17-0.28, p < 0.001). No correlation was found between SG and HADS, echocardiographic measures, age, gender, or education level (ρ S = 0.01-0.06).

Conclusions: SG is an acceptable and feasible method of assessing preferences in patients with severe AS that has evidence for validity. The inclusion of uncertainty lends the SG face validity in this population as a direct approach to assessing preferences and basis for QALY calculations.