. 2005 Jul;95(7):1259–1265. doi: 10.2105/AJPH.2004.039743

TABLE 2—

Proportion (SE) of Participants Who Were Abstinent During Phases 1 and 2 of Treatment: Results of Generalized Estimating Equation Model

			Prevalence Within Attendance Group (SE)
	Abstinence Prevalence (SE)^a		Low Attenders^b		High Attenders^c
	Phase 1	Phase 2	Phase 1	Phase 2	Phase 1	Phase 2
NH	0.41 (0.044)	0.18 (0.036)	0.25 (0.038)	0.08 (0.016)	0.56 (0.053)	0.25 (0.038)
NACH	0.60 (0.038)	0.40 (0.043)	0.42 (0.066)	0.21 (0.038)	0.64 (0.035)	0.51 (0.048)
ACH	0.69 (0.045)	0.46 (0.046)	0.45 (0.063)	0.29 (0.048)	0.82 (0.029)	0.60 (0.047)

Note. NH = no housing; NACH = non-abstinence-contingent housing; ACH = abstinence-contingent housing.

^aPhase 1 Wald tests showed an overall treatment effect (P < .0001), with pairwise differences between the NH and ACH groups (P < .0001) and the NH and NACH groups (P = .0015) but no evidence of a difference between the NACH group and the ACH group (P = .17). The results for phase 2 also showed an overall treatment effect (P = .0001), with pairwise differences between the NH and ACH groups (P < .0001) and the NH and NACH groups (P = .0003) but no evidence of a difference between the NACH group and the ACH group (P = .29).

^bAmong low attenders, phase 1 Wald tests showed an overall treatment effect (P = .010), with pairwise differences between the NH and ACH groups (P = .0080) and the NH and NACH groups (P = .032) but no evidence of a difference between the NACH group and the ACH group (P = .69). The results for phase 2 also showed an overall treatment effect (P = .0009), with pairwise differences between the NH and ACH groups (P = .0007) and the NH and NACH groups (P = .010) but no evidence of a difference between the NACH group and the ACH group (P = .21).

^cAmong high attenders, phase 1 Wald tests showed an overall treatment effect (P = .0005), with pairwise differences between the NH and ACH groups (P = .0004) and the ACH and NACH groups (P = .0011) but no evidence of a difference between the NACH group and the NH group (P = .26). The results for phase 2 also showed an overall treatment effect (P = .010), with pairwise differences between the NH and ACH groups (P = .0024) and the NH and NACH groups (P = .0011) but no evidence of a difference between the NACH group and the ACH group (P = .19).