Table 2.

Americans’ Changing Lives, 1986–2002; Physical Activity Over Time

	Physical activity
	Model 1		Model 2		Model 3		Model 4		Model 5
Sample size	3,360		3,360		3,360		3,360		3,343
No. of observations	9,757		9,757		9,757		9,757		9,617
Fixed effects
Intercept	2.61	***	2.61	***	2.63	***	2.65	***	2.66	***
Died during study	−0.42	***	−0.37	***	−0.38	***	−0.23	***	−0.18	***
Other attrition	−0.13	***	−0.06	*	−0.06		−0.05		−0.02
Baseline age	−0.01	***	−0.01	***	−0.01	***	−0.00	***	−0.01	***
Education			0.03	***	0.03	***	0.02	***	0.01	*
Race (White)			0.13	***	0.11	***	0.10	***	0.09	***
Gender (Men)			0.26	***	0.28	***	0.24	***	0.26	***
Time	−0.86 × 10−3	***	−0.85 × 10−3	***	−0.76 × 10−3	***	−0.07 × 10−3		−0.07 × 10−3
Interactions
Died during study × time	−0.65 × 10−3		−0.90 × 10−3		−0.94 × 10−3		−0.46 × 10−3		−0.25 × 10−3
Other attrition × time	0.73 × 10−3	*	0.45 × 10−3		0.55 × 10−3		0.48 × 10−3		0.41 × 10−3
Baseline age × time	−0.04 × 10−3	***	−0.04 × 10−3	***	−0.03 × 10−3	***	−0.02 × 10−3	**	−0.02 × 10−3	*
Education × time			−0.03 × 10−3		0.00 × 10−3		−0.02 × 10−3		−0.02 × 10−3
Race (White) × time			−1.07 × 10−3	***	−1.48 × 10−3	***	−1.50 × 10−3	***	−1.47 × 10−3	***
Gender (men) × time			0.26 x 10−3		0.50 × 10−3	*	0.34 × 10−3		0.19 × 10−3
Age × education					0.49 × 10−3	*	0.47 × 10-3	*	0.47 × 10-3	*
Age × race					−3.11 × 10−3	*	−2.36 × 10−3		−2.09 × 10−3
Age × gender					5.95 × 10−3	***	4.39 × 10−3	***	4.00 × 10−3	***
Age × education × time					0.02 × 10−4		0.01 × 10−4		0.01 × 10−4
Age × race × time					−0.06 × 10−3	**	−0.04 × 10−3	*	−0.05 × 10−3	**
Age × gender × time					0.03 × 10−3		0.02 × 10−3		0.01 × 10−3
Time-varying predictors
Blue collar	0.0001		−0.03		−0.02		−0.07	*	−0.05
SRH							0.08	***	0.07	***
Functional impairment							−0.18	***	−0.17	***
Underweight							−0.05		−0.03
Overweight							−0.08	***	−0.09	***
Married									0.09	***
Support									0.05	***
Integration									0.11	***
Mastery									0.01
Self-esteem									0.01
Random effects	Variance
Intercept, u0i	.325	***	.290	***	.288	***	.231	***	.218	***
Time slope, u1i	0.10 × 10−3	***	0.10 × 10−3	***	0.10 × 10−3	***	0.10 × 10−3	***	0.10 × 10−3	***
Level 1, ϵij	.263		.263		.263		.261		.251
Deviance	20513.50		20263.88		20329.17		19702.75		19133.97

Note: SRH = Self rated health.

*p ≤ .05; **p ≤ .01; ***p ≤ .001;  p ≤ .10.