Table 3.

Mean (95% CI) growth parameters for two-, three-, and four-class growth mixture models of living standards (LS) trajectories with age

	Est. population %†	Intercept (I)		Linear slope (S)		Factor covariance (I-S)‡	Description
		Mean (95% CI)	Variance‡	Mean (95% CI)	Variance‡	Mean (95% CI)
Two-class model
C21	87.4	25.4 (25.3 to 25.6)***	11.8***	0.1 (0.1 to 0.2) ***	0.3***	0.2 (−0.1 to 0.5)	Good LS
C22	12.6	12.4 (11.8 to 13.0)***	11.8***	0.8 (0.6 to 1.0) ***	0.3***	0.2 (−0.1 to 0.5)	Hardship, ↑ LS
Three-class model (optimal model)
C31	86.1	25.6 (25.4 to 25.7)***	11.2***	0.1 (0.1 to 0.2)***	0.1***	−0.1 (−0.2 to 0.0)	Good LS
C32	8.8	13.4 (12.6 to 14.2)***	11.2***	1.6 (1.4 to 1.7)***	0.1***	−0.1 (−0.2 to 0.0)	Hardship, ↑ LS
C33	5.1	12.4 (10.9 to 13.8)***	11.2***	−0.8 (−1.1 to −0.5)***	0.1***	−0.1 (−0.2 to 0.0)	Hardship, ↓ LS
Four-class model
C41	80.2	26.2 (26.0 to 26.4)***	6.6***	0.1 (0.1 to 0.2)***	0.1***	−0.0 (−0.2 to 0.1)	Good LS
C42	10.8	16.4 (15.5 to 17.4)***	6.6***	1.3 (1.0 to 1.5)***	0.1***	−0.0 (−0.2 to 0.1)	Hardship, ↑ LS
C43	5.6	17.2 (15.9 to 18.5)***	6.6***	−0.7 (−1.1 to −0.4)***	0.1***	−0.0 (−0.2 to 0.1)	Comfortable, ↓ LS
C44	3.4	6.7 (5.9 to 7.4)***	6.6***	0.3 (0.0 to 0.7)	0.1***	−0.0 (−0.2 to 0.1)	Hardship LS

Data weighted by response characteristics; model intercept represents mean ELSI-SF score ages 63–64.

*P<0.05, **P<0.01, ***P<0.001.

†Design-weighted proportions.

‡Partially restricted growth mixture model with between-class invariant variances and covariance.

↓, decrease with age; ↑, increase with age; ELSI-SF, Economic Living Standards Index Short Form; LS, living standards.