Table 2. Experimental Conditions.

Variable	Level 1	Level 2
Illness Severity	Leukemia: “…There are several different types of leukemia. Some … can spread to lymph nodes or the central nervous system if not treated. Leukemia can be fatal…”)	Sleep apnea: “…you are getting poor sleep at night, with very loud snoring, and sometimes it seems like you stop breathing or gasp for air during sleep….
AI Accuracy	Silent: No description of this issue provided in the vignette.	“Your doctor tells you that, based on scientific studies in leading journals, the AI system is proven more accurate at diagnoses compared to even specialist human physicians.”
AI Listens (Personal)	Silent: No description of this issue provided in the vignette.	“The Med-X clinic staff will carefully listen to understand your lifestyle, preferences, values, and goals. … you will have an extensive 45-minutes interview with a trained counselor, who will ask a range of questions to get your perspective on your healthcare.”
AI Tailored (Personal)	Silent: No description of this issue provided in the vignette.	“The AI system’s advice will be tailored to you. [It] will incorporate 36 different measurements and attributes specific to you to generate a unique and personalized treatment plan, just for you.”
AI Racial Unbiased	Silent: No description of this issue provided in the vignette.	“Although research suggests that human physicians can be biased by racial and ethnic stereotypes, the AI system has been carefully designed and tested to ensure that treatment recommendations are unbiased.”
AI Financial Unbiased	Silent: No description of this issue provided in the vignette.	“Although research suggests that human physicians can be biased by their financial relationships with drugmakers and insurance companies, the AI system has been carefully designed and tested to ensure that treatment recommendations are unbiased.”
PCP Incorporates AI Advice	Defer-Portal: “Your doctor explains, ‘From either clinic, you will receive the results as an electronic message in your patient portal, the next day. It will tell you the diagnosis and what to do next.’“	Incorporate-Explain: “Your doctor explains, “When we get the results back from either clinic, I will explain them and talk them through with you. I will incorporate the results into my ultimate opinion on what we should do next.’”
PCP Nudges toward AI	None: “Your doctor says, ‘We can get you into either Dr. Williams or the Med-X AI clinic; it is your choice.’”	Default-Easy: “Your doctor says, ‘For some time, I have been recommending the Med-X AI clinic for all my patients, and the nurse has already confirmed available appointments for you. But if you prefer to see Dr. Williams, I can give you a referral instead. It is your choice.’”

Note: For the unbiased and personalization variables, when both types (race and financial, or listens and tailored) were presented, the text was concisely integrated into a single statement, as shown in the survey text at osf.io/9y26x.