Table 1.
Characteristics of the study population at baselinea
| Total Sample (n = 127) | Contingency Management (n = 70) | Control (n = 57) | |
|---|---|---|---|
| Recruitment | |||
| Peer-referral | 64 (50) | 35 (50) | 29 (51) |
| Healthcare provider, STD or HIV clinic | 28 (22) | 15 (21) | 13 (24) |
| Self-referral via community advertising | 21 (16) | 13 (19) | 8 (14) |
| Community-based organization | 7 (5) | 4 (6) | 3 (5) |
| Other, unknown | 7 (5) | 3 (4) | 4 (7) |
| Randomization | |||
| 1:1 | 100 (79) | 50 (71) | 50 (88) |
| 3:1 | 27 (21) | 20 (29) | 7 (12) |
| Demographics | |||
| Age (years, median [range]) | 39 (18-60) | 40 (18-60) | 37 (19-57) |
| Race/Ethnicityb | |||
| Black, African American | 10 (8) | 2 (3) | 8 (14) |
| Hispanic, Latino | 17 (13) | 12 (17) | 5 (9) |
| Native American, Alaska Native | 8 (6) | 4 (6) | 4 (7) |
| White | 76 (60) | 47 (67) | 29 (51) |
| Other race/ethnicity, multiracial, unknown | 16 (13) | 5 (7) | 11 (19) |
| Education | |||
| Less than High School | 19 (15) | 10 (14) | 9 (16) |
| High School | 30 (24) | 17 (24) | 13 (23) |
| Some college, vocational/technical training | 60 (47) | 35 (50) | 25 (45) |
| College or greater | 13 (10) | 6 (9) | 7 (12) |
| Missing | 5 (4) | 2 (3) | 2 (4) |
| Annual income less than $15,000 | 90 (71) | 53 (76) | 37 (65) |
| Homeless or marginally housed | 27 (21) | 17 (24) | 10 (17) |
| Neither employed nor attending school | 89 (70) | 51 (73) | 38 (67) |
| HIV status | |||
| Negative | 57 (45) | 30 (43) | 27 (47) |
| Positive | 70 (55) | 40 (57) | 30 (53) |
| Sexual orientation | |||
| Gay, homosexual | 80 (63) | 47 (67) | 33 (58) |
| Bisexual | 28 (22) | 14 (20) | 14 (25) |
| Straight, heterosexual | 1 (1) | 1 (1) | 0 |
| Queer, same gender loving, other | 18 (14) | 8 (11) | 10 (17) |
| Sexual Behavior, prior 6 weeks | |||
| Number of sex partners (median [IQR]) | 3 (2-8) | 4 (2-10) | 3 (2-6.5) |
| Number of anal sex partners (median [IQR]) | 2 (1-5) | 2 (1-6) | 2 (1-5) |
| Number of nonconcordant UAI partners (median [range]) | 0 (0-35) | 0 (0-35) | 0 (0-16) |
| Nonconcordant UAI | 35 (28) | 21 (30) | 14 (25) |
| Use of methamphetamine with anal sex | 102 (80) | 59 (84) | 43 (75) |
| Exchanged sex for methamphetamine | 20 (16) | 11 (16) | 9 (16) |
| Methamphetamine Use | |||
| Duration of methamphetamine use, years (median [IQR]) | 11 (5-19) | 14 (6-19) | 11 (5-16) |
| Weekly or daily methamphetamine use, prior 6 weeks | 83 (65) | 51 (73) | 32 (56) |
| Used more than 8 quarters of methamphetamine, prior 6 weeks | 59 (46) | 37 (53) | 22 (39) |
| Injection of methamphetamine, prior 6 weeks | 69 (54) | 41 (59) | 28 (49) |
| 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) | 49 (39) | 25 (36) | 24 (42) |
| "Yes, I have been trying for less than 6 months" (Action) |
24 (19) | 12 (17) | 12 (21) |
| "No, but I really want to start this month" (Preparation) | 14 (11) | 11 (16) | 3 (5) |
| "No, but I really would like to try in the next 6 months" (Contemplation) | 14 (11) | 9 (13) | 5 (9) |
| "No, and I am really not interested in trying" (Pre-contemplation) | 6 (5) | 3 (4) | 3 (5) |
| Missing | 20 (16) | 10 (14) | 10 (17) |
| Ever been in substance abuse treatment for methamphetamine use | 32 (25) | 17 (24) | 15 (26) |
| Ever attended a support group for methamphetamine use | 52 (41) | 25 (36) | 27 (47) |
| Other substance use, prior 6 weeks | |||
| Cocaine | 35 (28) | 17 (24) | 18 (32) |
| Crack | 53 (42) | 26 (37) | 27 (47) |
| Inhaled nitrites | 59 (46) | 35 (50) | 24 (42) |
| Erectile dysfunction medications | 39 (31) | 26 (37) | 13 (23) |
| Ecstasy | 19 (15) | 8 (11) | 11 (19) |
| Gamma-hydroxybutyrate | 25 (20) | 16 (23) | 9 (16) |
| Urine testing results | |||
| Urine positive for methamphetamine | 44 (35) | 28 (40) | 16 (28) |
| Urine positive for cocaine metabolites | 31 (24) | 12 (17) | 19 (33) |
| Urine positive for methamphetamine or cocaine metabolites | 65 (51) | 35 (50) | 30 (53) |
IQR, interquartile range; UAI, unprotected anal intercourse.
aData are n (%) unless otherwise noted.
b P < 0.05