Table 4.

Results of regression analyses for predicting proliferative response of peripheral blood leukocytes to a monoclonal antibody to T-cell receptor (T3) across three dilutions

	Dependent variable: proliferative response at dilutions
	128:1	64:1	32:1
Model A, R2A*	.026	.052	.064
Model AA, R2AA†	.088	.104	.143
Model B‡
R2B	.155	.160	.200
R2B–AA§	.067	.056	.057
βStress∥	−.273	−.249	−.252
t(df = 101)¶	−2.747	−2.514	−2.604
P	.008	.014	.012
Model C#
R2C	.102	.092	.094
t(df = 101)¶	−3.452	−3.255	−3.307
P	.002	.002	.002

^*Model A includes the control predictors of age, stage, and days since surgery for the immune outcome, proliferative response. The R²_A is the total variance in proliferation explained by these three predictors.

^†Model AA includes model A variables plus the control predictor of number of T cells for the immune outcome, proliferation. The R²_AA is the total variance in proliferation explained by these four predictors.

^‡Model B includes model AA control variables plus the stress predictor (i.e., Impact of Event Scale [IES] score) for the immune outcome, proliferation. The R²_B is the total variance in proliferation explained by the four control predictors and the stress predictor.

^§R²_B–AA is the increment in variance due to stress only (i.e., variance beyond that explained by the control predictors) in predicting the proliferation outcome.

^∥β_Stress is the standardized beta (β) for the stress variable in model B. It indicates the magnitude and direction of the influence (negative) of stress on the immune outcome.

^¶df refers to the degrees of freedom in model B.

^#Model C includes stress as the only predictor of the immune outcome, proliferation. The R²_C is the total variance in proliferation explained by stress; this model provides the simple association between psychologic stress and immune function.