Table 2.

Latent Growth Model of Walking Speed With Age and Wealth, England 2002–2003 to 2006–2007

Growth Parameters	Estimate	95% CI
Intercept	0.715	0.701, 0.729
Intercept variance	0.032	0.028, 0.036
Slope	−0.020	−0.030, −0.010
Slope variance	0.008	0.006, 0.010
Intercept regressed on
Baseline age, 71 y	−0.012	−0.012, −0.012
Wealth—middle	0.112	0.096, 0.128
Wealth—richest	0.220	0.200, 0.240
Slope regressed on
Baseline age, 71 y	−0.003	−0.003, −0.003
Wealth—middle	−0.015	−0.027, −0.003
Wealth—richest	−0.027	−0.041, −0.013
Model Fit	Estimate	Df
Chi-square test	6314.9	12
CFI	0.995
TLI	0.985
RMSEA	0.033
N	7,225

Note: CFI = Comparative Fit Index; RMSEA = root-mean-square error of approximation; TLI = Tucker–Lewis index (TLI).