Table 3.

Final proportional hazards regression results for overall attrition.

Model Fit				Step 3 Predictor Statistics
Model	df	−2LL	Δ-2LL	Predictor	β	HR	HR 95% LL	HR 95% UL
Step 1	1	365,405.94	—	AFQT	−0.173	0.841	0.820	0.862
Step 2	11	364,785.55	620.39	Achievement	−0.012	0.988	0.964	1.014
Step 3	17	364,671.91	113.64	Adjustment	−0.002	0.998	0.974	1.024
				Dominance	−0.024	0.976	0.959	0.993
				Even-tempered	−0.041	0.960	0.944	0.976
				Intellectual Efficiency	0.080	1.083	1.064	1.103
				Optimism	−0.031	0.970	0.953	0.986
				Physical Conditioning	−0.227	0.797	0.778	0.817
				Self-Control	−0.021	0.979	0.963	0.996
				Selflessness	0.088	1.091	1.065	1.118
				Sociability	0.022	1.022	0.997	1.048
				Time x AFQT	−0.003	0.997	0.996	0.999
				Time x Achievement	−0.002	0.998	0.997	0.999
				Time x Adjustment	0.002	1.002	1.001	1.003
				Time x Physical Conditioning	0.005	1.005	1.003	1.006
				Time x Selflessness	−0.002	0.998	0.997	0.999
				Time x Sociability	0.002	1.002	1.001	1.003

n = 72,009. −2LL = − 2 log likelihood. β = standardized parameter. HR = Hazard ratio. 95% LL = 95% confidence interval lower limit of the hazard ratio. 95% UL = 95% confidence interval upper limit of the hazard ratio. The Step 1 model includes the AFQT only. The Step 2 model adds the TAPAS scale main effects to the Step 1 model. The Step 3 model adds the interaction terms (i.e., time-varying effects) to the Step 2 model. All models are significant, p < .05. The Step 2 and 3 models resulted in significant change in model fit compared to the previous steps based on a Likelihood Ratio χ2 test, p< .05. Bolded values indicate significant predictor effects, p < .05.