Menza et al. BMC Public Health 2010, 10:774 http://www.biomedcentral.com/1471-2458/10/774 Table 1 Characteristics of the study population at baselinea Recruitment Randomization Demographics Age (years, median [range]) Race/Ethnicityb Education Annual income less than $15,000 Homeless or marginally housed Neither employed nor attending school HIV status Sexual orientation Peer-referral Healthcare provider, STD or HIV clinic Self-referral via community advertising Community-based organization Other, unknown 1:1 3:1 Black, African American Hispanic, Latino Native American, Alaska Native White Other race/ethnicity, multiracial, unknown Less than High School High School Some college, vocational/technical training College or greater Missing Negative Positive Gay, homosexual Bisexual Straight, heterosexual Queer, same gender loving, other Sexual Behavior, prior 6 weeks Number of sex partners (median [IQR]) Number of anal sex partners (median [IQR]) Number of nonconcordant UAI partners (median [range]) Nonconcordant UAI Use of methamphetamine with anal sex Exchanged sex for methamphetamine Methamphetamine Use Duration of methamphetamine use, years (median [IQR]) Weekly or daily methamphetamine use, prior 6 weeks Used more than 8 quarters of methamphetamine, prior 6 weeks Injection of methamphetamine, prior 6 weeks Trans-theoretical stage of change: “Have you been trying to stop or cut down on your methamphetamine use?” “Yes, I have been trying for more than 6 months” (Maintenance) “Yes, I have been trying for less than 6 months” (Action) 64 (50) 28 (22) 21 (16) 7 (5) 7 (5) 100 (79) 27 (21) 39 (18-60) 10 (8) 17 (13) 8 (6) 76 (60) 16 (13) 19 (15) 30 (24) 60 (47) 13 (10) 5 (4) 90 (71) 27 (21) 89 (70) 57 (45) 70 (55) 80 (63) 28 (22) 1 (1) 18 (14) 3 (2-8) 2 (1-5) 0 (0-35) 35 (28) 102 (80) 20 (16) 11 (5-19) 83 (65) 59 (46) 69 (54) 49 (39) 24 (19) Total Sample (n = 127) Contingency Management (n = 70) Control (n = 57) 40 (18-60) 37 (19-57) 35 (50) 15 (21) 13 (19) 4 (6) 3 (4) 50 (71) 20 (29) 2 (3) 12 (17) 4 (6) 47 (67) 5 (7) 10 (14) 17 (24) 35 (50) 6 (9) 2 (3) 53 (76) 17 (24) 51 (73) 30 (43) 40 (57) 47 (67) 14 (20) 1 (1) 8 (11) 4 (2-10) 2 (1-6) 0 (0-35) 21 (30) 59 (84) 11 (16) 14 (6-19) 51 (73) 37 (53) 41 (59) 25 (36) 12 (17) Page 6 of 13 29 (51) 13 (24) 8 (14) 3 (5) 4 (7) 50 (88) 7 (12) 8 (14) 5 (9) 4 (7) 29 (51) 11 (19) 9 (16) 13 (23) 25 (45) 7 (12) 2 (4) 37 (65) 10 (17) 38 (67) 27 (47) 30 (53) 33 (58) 14 (25) 0 10 (17) 3 (2-6.5) 2 (1-5) 0 (0-16) 14 (25) 43 (75) 9 (16) 11 (5-16) 32 (56) 22 (39) 28 (49) 24 (42) 12 (21)