Psychometric benefits of adding bolt-ons to the EQ-5D-5L in populations undergoing minimally invasive cosmetic procedures.

Objectives: There is growing interest in measuring health outcomes associated with minimally invasive cosmetic procedures (MICPs), such as botulinum toxin and hyaluronic acid injections. However, the EQ-5D may have limited content validity for this purpose. This study aims to psychometrically test five additional dimensions ('bolt-ons') for the EQ-5D-5L in individuals planning or undergoing MICPs.

Methods: In 2023, a cross-sectional, online survey was conducted with 149 women planning MICPs and 215 who had recently undergone them. Respondents completed the EQ-5D-5L, five bolt-ons (skin irritation, self-confidence, sleep, social relationships, tiredness), the Rosenberg Self-Esteem Scale (RSES) and the Brief Fear of Negative Evaluation Scale-Straightforward Items (BFNE-S). The following psychometric properties were tested for the EQ-5D-5L + bolt-on(s): ceiling, convergent and divergent validity, explanatory power and known-groups validity.

Results: Adding tiredness (22%), self-confidence (23%) or sleep bolt-ons (27%) substantially reduced the ceiling of the EQ-5D-5L (47%). The self-confidence and social relationships bolt-ons showed a moderate or strong correlation with the RSES and BFNE-S total scores (-0.462 to -0.679). The tiredness and self-confidence bolt-ons improved the EQ-5D-5L's explained variance in EQ VAS scores from 37% to 45%. The self-confidence and social relationships bolt-ons improved the EQ-5D-5L's discrimination between known groups based on self-esteem and bodily appearance (relative efficiency: 2.72 to 2.82).

Conclusions: Relevant bolt-ons substantially enhance the psychometric performance of the EQ-5D-5L in MICP populations. The self-confidence and tiredness bolt-ons may be recommended as primary choices for use alongside the EQ-5D-5L, both in clinical studies and as part of sensitivity analyses in economic evaluations of MICPs.