Survey construction: Patient volunteer and health utility measurements

Upon Institutional Review Board approval of study design, recruitment for a transfeminine patient volunteer was conducted at the vocal gender dysphoria clinic of our coauthor (J.T.). All patient volunteers in consideration were managed per transgender voice and communication treatment guidelines per World Professional Association for Transgender Health (WPATH, 2016), had pretreatment/pre-operative and post-treatment/post-operative phonometrics, underwent vocal feminization which included feminization laryngoplasty with perioperative voice therapy by a speech-language pathologist. Voice therapy included conversation therapy training, nonverbal communication strategies, and resonant voice therapy. Perioperative phonometrics included standardized speaking passages (“Long ago, men found it easier to travel on water than on land. They needed a cleared path or road when traveling on land, but on water, a log of wood or any large object that would float became a man’s boat”; see ESupplement). Based on previously-published data about feminization laryngoplasty outcomes, a volunteer with median phonometric outcomes observed (Thomas & MacMillan, 2013) was selected for use of peri-treatment speaking passages for this study; the volunteer’s pronouns were she/her/hers.

Based on qualitative and quantitative reports (Dacakis et al., 2017; Davies et al., 2015; Hancock, 2018; Hancock et al., 2011; Nolan et al., 2019; Oates & Dacakis, 2015; Song & Jiang, 2017; Verbeek et al., 2020), and in the typical health utility state fashion (Morimoto & Fukui, 2002) descriptions sketching the state of pretreatment transfeminine vocal gender dysphoria were created. This health state, as well as the post-treatment transfeminine health state, and a monocular and binocular blindness control, were used for the survey (ESupplement).

For each of these health states, the health utility scores were measured using VAS, SG, and TTO measures. Each measure generates a fraction of a quality-adjusted life year (QALY), a value that signifies disease burden whereupon one QALY equates to one year in perfect health.

The VAS used in health utility studies is a sliding scale continuum with anchors representing worst possible health (death, i.e. score 0) and best possible health (perfect health, i.e. score 100) on opposing ends, with respondents asked to rate health state (Parkin & Devlin, 2006). The VAS would then generate a value x, whereupon x/100 would represent the health utility of that heath state queried as a QALY.

The SG involves presenting individuals with a choice between two options: the health state queried that is certain and unchangeable for duration of life and a gamble with one ideal (perfect health) and one worst-case (death) outcome possible (Lenert et al., 1998). Respondents are then asked what probability of the ideal outcome would make them indifferent between remaining in the health state surveyed for certain or choosing death. This probability would then represent the QALY generated by the SG. In this study, participants were first presented a specific risk of death starting at 0%, which if accepted, progressed to serially-increased risks that was uptitrated by 5% until the risk of death was 100%, in an “bottom-up” manner. Compared to other elicitation methods, a “bottom-up” manner is a well-validated elicitation method suggested to have more reduced variability between subjects (Lenert et al., 1998).

The TTO asks subjects to consider the life-years they would be willing to sacrifice to avoid the health state queried in favor for perfect health, represented by y (Arnesen & Trommald, 2005). Based on reported average of hormone therapy initiation for transfeminine patients at 31 years (Beckwith et al., 2017), the 2015 United States Transgender Survey’s findings that the majority of transgender patients started gender-affirmation-related treatments between 18 and 44 years (James et al., 2016), and approximate average life expectancy in the US of 78 years, 47 years was chosen as the maximum number of time that one can choose to live without trading off years. In this study, y was uptitrated from a “bottom-up” fashion similar to the SG measure. The QALY was then calculated as (47 – y)/47.