Table 1.

Study Location and Sample Participant Characteristics

Variable	Number of studies (%)
Location
International	16 (16.0)
US	80 (80.0)
Both international and US	2 (2.0)
Not reported or unclear	2 (2.0)
Type of location
Rural or frontier	4 (4.0)
Urban	26 (26.0)
Sub-urban	2 (2.0)
Other	1 (1.0)
Multiple types of locations	4 (4.0)
Not applicable (outside of US or unclear)	20 (20.0)
Not reported or unclear	43 (43.0)
Race / Ethnicity (only among US articles)
White	2 (2.0)
Black or African American	14 (14.0)
Asian	5 (5.0)
Pacific Islander or Hawaiian Native	0 (0)
American Indian or Alaska Native	1 (1.0)
Latino / Hispanic	19 (19.0)
Other	2 (2.0)
Multiple races a	28 (28.0)
Not applicable (outside of US)	20 (20.0)
Not reported or unclear	9 (9.0)
Gender
Female	50 (50.0)
Male	7 (7.0)
Both	39 (39.0)
Not reported	4 (4.0)
Age
Focused on young adults (18-24)	0 (0)
Focused on adults, generally	74 (74.0)
Focused on older adults (65+)	2 (2.0)
Not reported or unclear	24 (24.0)

^aOf articles that included multiple races (n=28), most included 3 races (n=12, 12% of all studies) or 4 races (n=10, 10% of all studies).