Table 1.

Variables and survey measurements.

Variable			Survey measurement
Patient-perceived quality of care			Overall, how would you rate the quality of health care you received in the past 12 months? (1=poor to 5=excellent)
Use of electronic communication
	1	In the past 12 months, have you used a computer, smartphone, or other electronic means to communicate with a doctor or a doctor’s office? (1=yes, 0=no)
	2	Have you sent a text message to or received a text message from a doctor or other health care professional within the last 12 months? (1=yes, 0=no)
	3	In the past 12 months, have you used your online medical record to securely message health care provider and staff (eg, email)? (1=yes, 0=no)
	4	In the past 12 months, have you used your online medical record to add health information to share with your health care provider, such as health concerns, symptoms, and side effects? (1=yes, 0=no)
	5	Have you shared health information from either an electronic monitoring device or smartphone with a health professional within the last 12 months? (1=yes, 0=no)
	6	Have you electronically sent your medical information to another health care clinician? (1=yes, 0=no).
Sociodemographics
	1	Age (young: ≥18 and <45 years, middle-aged: ≥45 and <65 years, and older adults ≥65 years)
	2	Sex (0=male, 1=female)
	3	Education level (0=less than high school, 1=high school graduate, 2=some college, 3=college graduate or more)
	4	Marital status (0=not married, 1=married or partnered)
	5	Race/ethnicity (0=White, 1=African American, 2=Hispanic, 3=other)
	6	Household income (0=<US $50,000; 1=≥US $50,000)
	7	Living status (0=living with others, 1=living alone)
	8	Residency (0=nonrural, 1=rural)
Comorbidities			The number of comorbidities: Has a doctor or other health professional ever told you that you had any of the following medical conditions? Choices for this question included cancer, hypertension, diabetes, heart condition, chronic lung disease, and depression, and a sum score was used.
Patient-clinician relationship
	1	Having a regular health care provider: Not including psychiatrists and other mental health professionals, is there a particular doctor, nurse, or other health professional that you see most often? (0=no, 1=yes)
	2	Trusting a doctor: In general, how much would you trust information about health or medical topics from a doctor? (1=not at all to 4=a lot)