From: Estimating correlation between multivariate longitudinal data in the presence of heterogeneity
Variables | Mean ± SD or N (%) | Estimated fixed and random effects ± standard errors | |||
---|---|---|---|---|---|
Univariate mixed model | Bivariate mixed model | ||||
MD | VA | MD | VA | ||
Fixed effects: | |||||
Intercept | - | −2.26 ± 0.34# | 50.75 ± 1.03# | −2.23 ± 0.34# | 50.88 ± 1.00# |
Slope | - | −0.35 ± 0.04# | −0.60 ± 0.11# | −0.35 ± 0.04# | −0.69 ± 0.11# |
Age (years) | 65.7 ± 9.5 | −0.49 ± 0.15# | −3.45 ± 0.43# | −0.43 ± 0.14# | −3.07 ± 0.42# |
IOP (mmHg) | 22.3 ± 6.2 | −0.55 ± 0.16# | −0.55 ± 0.47 | −0.55 ± 0.16# | −0.40 ± 0.45 |
CCT (μm) | 558.4 ± 37.8 | 0.35 ± 0.15* | −0.07 ± 0.45 | 0.35 ± 0.15* | −0.22 ± 0.44 |
HCD | 0.53 ± 0.19 | 0.20 ± 0.15 | 0.12 ± 0.44 | 0.20 ± 0.15 | 0.12 ± 0.44 |
Male | 150 (56%) | 0.11 ± 0.29 | 0.77 ± 0.87 | 0.06 ± 0.29 | 1.01 ± 0.84 |
African American | 89 (33%) | −0.57 ± 0.31 | −2.13 ± 0.94* | −0.58 ± 0.31 | −2.15 ± 0.91* |
Observation group | 158 (59%) | −0.08 ± 0.32 | −0.26 ± 0.94 | −0.10 ± 0.32 | −0.69 ± 0.92 |
Random effects:& | |||||
Var(Ek) | 2.03 ± 0.06# | 19.15 ± 0.96# | 2.02 ± 0.06# | 19.19 ± 0.96# | |
Var(Ik) | 5.05 ± 0.51# | 39.25 ± 4.69# | 5.09 ± 0.51# | 38.77 ± 4.63# | |
Var(Sk) | 0.29 ± 0.04# | 1.35 ± 0.25# | 0.29 ± 0.04# | 1.35 ± 0.24# | |
Cov(Ik, Sk) | 0.62 ± 0.10# | −1.23 ± 0.83 | 0.63 ± 0.10# | −0.73 ± 0.79 | |
Cov(I1, I2) | - | - | - | 3.88 ± 1.17# | |
Cov(S1, S2) | - | - | - | 0.37 ± 0.08# | |
Cov(I1, S2) | - | - | - | 1.16 ± 0.27# | |
Cov(I2, S1) | - | - | - | 0.67 ± 0.31* |