Table 4.

HIV risk behaviors

Variable	Standard care	CM	Significance test value (df), p-value	Effect size Cohen’s d
Baseline Past 3-month Total Score	3.8 ± 4.6	4.4 ± 4.1	t (235) = 0.98, p =.33
Drug score	0.5 ± 2.2	0.3 ± 1.8	t (235) = 0.81, p =.42
Sexual score	3.3 ± 3.8	4.0 ± 3.8	t (235) = 1.54, p =.12
Month 1 Total Change Score	−0.1 ± 3.7	−1.2 ± 3.9	t (225) = 2.35, p < .02	0.29
Drug change score	0.1 ± 1.5	−0.3 ± 1.5	t (225) = 1.17, p = .24	0.20
Sexual change score	0.0 ± 3.3	−1.0 ± 3.7	t (225) = 2.07, p < .04	0.29
Month 3 Total Change Score	0.1 ± 5.2	0.2 ± 5.0	t (217) = −0.08, p = .94	−0.02
Drug change score	0.1 ± 2.6	−0.1 ± 2.1	t (217) = 0.63, p = .53	0.08
Sexual change score	0.1 ± 3.9	0.3 ± 4.4	t (217) = −0.46, p = .65	−0.05
Month 12 Total Change Score	1.6± 6.3	−0.3 ± 5.0	t (211) = 2.49, p < .02
Drug change score	0.3± 3.4	−0.1 ± 2.4	t (211) = 0.96, p = .34	0.13
Sexual change score	1.3 ± 4.4	−0.3 ± 4.3	t (211) = 2.55, p < .01	0.36

Notes: Change score values represent means and standard deviations of change scores, calculated by subtracting baseline past 3-month scores from during or post-treatment scores, such that negative scores represent reductions and positive scores reflect increases in risk behaviors. Note that Month 1 change scores represent scores reflecting risk behaviors from the past 1 month minus baseline risk behaviors assessed over the past 3 months. CM=contingency management.