Table 1.
Demographic characteristics and baseline variables based on age category
| Variable | Age 18-29 (n=70) |
Age 30-39 (n=186) |
Age ≥ 40 (n=137) |
Statistical test, p value |
|---|---|---|---|---|
| Recruitment site (no., %) | X2(6) = 5.12, p= 0.53 | |||
| Site A | 5 (7.1) | 16 (8.6) | 10 (7.3) | |
| Site B | 22 (31.4) | 54 (29.0) | 55 (40.1) | |
| Site C | 21 (30.0) | 61 (32.8) | 40 (29.2) | |
| Site D | 22 (31.4) | 55 (29.6) | 32 (23.4) | |
| Treatment group (no.,%) | X2(2) = 0.05, p = 0.98 | |||
| Contingency Management | 20 (28.6) | 54 (29.0) | 41 (29.9) | |
| Standard Care | 50 (71.4) | 132 (70.1) | 96 (70.1) | |
| Studies (no., %) | X2(4) = 6.30, p = 0.18 | |||
| Petry et al. (2004) | 25 (35.7) | 62 (33.3) | 33 (24.1) | |
| Petry et al. (2005a) | 23 (32.9) | 70 (37.6) | 49 (35.8) | |
| Petry et al. (2006a) | 22 (31.4) | 54 (29.0) | 55 (40.1) | |
| Female (no.,%)* | 32 (45.7)a | 80 (43.0)a | 85 (62.0)b | X2(2) = 12.10, p = 0.003 |
| Ethnicity (no.,%)* | X2(6) = 30.80, p = 0.000 | |||
| African American | 17 (24.3)a | 110 (59.1)b | 79 (57.7)b | |
| Caucasian | 40 (57.1)a | 51 (27.4)b | 45 (32.8)b | |
| Hispanic | 10 (14.3) | 22 (11.8) | 12 (8.8) | |
| Other | 3 (4.3) | 3 (1.6) | 1 (0.7) | |
| Marital status (no.,%)* | X2(6) = 39.44, p = 0.000 | |||
| Never married | 52 (74.3)a | 109 (58.6)b | 49 (35.8)c | |
| Married/Living with partner | 13 (18.6) | 32 (17.2) | 30 (21.9) | |
| Separated/Divorced | 5 (7.1)a | 44 (23.7)b | 54 (39.4)c | |
| Widowed | 0 (0.0) | 1 (0.5) | 4 (2.9) | |
| Annual income | $9,580 (11,090) |
$8,790 (16,410) |
$10,820 (14,350) |
F(2,390) = 0.73, p = 0.48 |
| Years of education | 11.5 (1.5) | 11.5 (1.6) | 11.8 (1.7) | F(2,390) = 1.82, p = 0.16 |
| Cocaine, opioid, or alcohol positive sample at intake (no.,%) |
15 (21.4) | 32 (17.3) | 26 (19.0) | X2(2) = 0.59, p = 0.75 |
| Past year DSM alcohol dependence (no.,%)* |
24 (34.3) | 97 (52.2) | 84 (61.3) | X2(2) = 13.56, p = 0.001 |
| Past month days of use | ||||
| Cocaine | 4.7 (7.8) | 3.7 (6.4) | 3.0 (5.8) | F(2,390) = 1.67, p = 0.19 |
| Cannabis* | 3.7 (8.6)a | 1.8 (5.7)b | 1.0 (3.4)b | F(2,390) = 5.49, p = 0.004 |
| Alcohol | 1.1 (3.1) | 2.7 (6.0) | 2.8 (5.9) | F(2,390) = 2.51, p = 0.08 |
| Opioids* | 1.0 (3.6)a | 0.1 (0.8)b | 1.2 (4.7)a | F(2,390) = 4.61, p = 0.01 |
| No. of alcohol treatments* | 1.0 (2.8)a | 3.0 (7.0)a | 6.8 (21.4)b | F(2,390) = 5.08, p = 0.007 |
| No. of drug treatments* | 2.8 (5.5)a | 4.6 (7.5)a | 7.4 (13.6)b | F(2,390) = 6.00, p = 0.003 |
| No. of inpatient psychiatric treatments |
0.6 (1.5) | 0.8 (1.7) | 1.2 (3.3) | F(2,390) = 2.06, p = 0.13 |
| No. of outpatient psychiatric treatments |
1.4 (3.1) | 1.2 (3.1) | 1.1 (2.3) | F(2,390) = 0.23, p = 0.79 |
Values represent means and (standard deviations) unless indicated.
*
Significant between group difference.
Different subscripts represent groups that differ significantly (p<.05) using Student Newman Keuls tests.