Table 1.

Comparison of intervention arms: inputs, outcomes, and cost-effectiveness

Item	STD (N=122)	RP (N=135)	TEL (N=102)
(a) Number of planned counselor contacts per client (with actual numbers in parentheses)
Individual sessions	0.0 (0.1)	12.0 (7.2)	1.0 (1.0)
Group sessions	24.0 (14.1)	12.0 (7.1)	4.0 (4.3)
Telephone sessions	0.0 (0.0)	0.0 (0.0)	11.0 (5.7)
Total	24.0 (14.2)	24.0 (14.3)	16.0 (11.0)
(b) Planned contact time per client
Client hours	56.6	50.0	17.8
Counselor hours	6.0	16.0	5.3
(c) Outcomes per client, 2 years
Effectiveness: Average % abstinent each quarter	46.7%	51.7%	57.1%
Incremental effectiveness	Reference	5.0%	10.4%
95% confidence interval	n.a.	[−3.2%; 13.2%]	[0.1%; 20.7%]
Program cost	$511	$1,363	$454
Value of client time and travel	$359	$322	$115
Societal cost	$870	$1,684	$569
(d) Incremental cost
Program cost over 2 years	Reference	$852	−$57
Program cost per year	Reference	$426	−$29
Societal cost over 2 years	Reference	$814	−$301
Societal cost per year	Reference	$407	−$151
(e) Cost-effectiveness (perspective)
ICER (program)	Reference	$8,500	−$300
95% confidence interval		[$3,200; infinity]	[−$30,700; −$100]
ICER (societal)	Reference	$8,100	−$1,400
95% confidence interval		[$3,100; infinity]	[−$161,900; −$700]

Notes: STD denotes standard continuing care program; RP denotes relapse prevention program; TEL denotes continuing care delivered over the telephone program; n.a. denotes not applicable. Incremental (Incr.) effectiveness uses STD as the reference. ICER denotes incremental cost-effectiveness ratio (incremental cost per abstinent year) compared to reference category (STD). Statistical significance of incremental effectiveness of RP, based on RP vs. STD contrast, is 0.24; that of TEL, based on TEL vs. STD contrast, is 0.047 (McKay et al., 2005a). Costs are in 2005 prices.