TABLE 3.

Multivariate Models of Intervention Costs and Benefits^a

Covariate	Organizational Costsb	Intervention Costsc
STAR participant	−1,850.20 (2,547.46)	690.13*** (14.41)
Baseline costs to employer	2.15*** (0.356)
Male	1,922.33 (3,177.68)	−18.99 (12.30)
Age	−705.35*** (176.98)	3.45*** (0.99)
Race
Indian	7,650.25 (4,975.05)	−15.58 (20.32)
Nonwhite, non-Indian	−3,667.41 (3,503.73)	−32.08 (17.12)
College graduate	339.52 (2,656.79)	12.89 (17.76)
Constant		−84.54 (62.25)
Observations	946	946
Adjusted meansd
Control	28,497.02 (2,158.88)	16.15 (6.67)
STAR	26,646.81 (1,582.61)	706.28 (12.18)
ROIe	1.68 (−8.85 to 9.47)

^*P < 0.001.

^aDependent variables expressed in US dollars, 2011 prices.

^bMarginal effects from Gamma GLM regression with cluster-robust standard errors in parentheses. Model also controls for number of missed data collection waves, calendar quarters, and randomization factors.

^cOLS regression with cluster-robust standard errors in parentheses. Model also controls for randomization factors.

^dAdjusted means (standard errors) computed using recycled predictions.

^eROI calculated as ΔE − ΔΨΔΨ where ΔE is the marginal effect of STAR on organizational costs and ΔC is the marginal effect of STAR on intervention costs. The confidence interval (in parentheses) was calculated from the empirical distribution of ROI point estimates using a cluster-robust bootstrap routine with 1000 replications.⁵⁶

ROI, return on investment; STAR, support, transform, achieve, results.