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. Author manuscript; available in PMC: 2013 May 28.
Published in final edited form as: Stat Med. 2012 Aug 3;31(26):3192–3210. doi: 10.1002/sim.5393

Table I.

Results from 1000 simulations under the three-level mixed-effects location scale model - three continuous covariates and small random scale effect and positive covariance.

Three-level Random Intercept Model
Three-level Mixed-effects Location Scale Model
Parameters True Value EST SE* Bias SB RMSE 95% COV AW EST SE* Bias SB RMSE 95% COV AW
β0 : (Intercept) 6.90 6.899 0.06 -0.0012 -2.16 0.06 95.9 0.23 6.899 0.06 -0.0011 -1.99 0.06 95.8 0.23
β1 : (X1) -0.40 -0.400 0.03 0.0002 0.80 0.03 95.4 0.11 -0.400 0.02 0.0003 1.13 0.02 94.5 0.10
β2 : (X2) 0.20 0.200 0.01 0.0001 0.50 0.01 95.5 0.06 0.200 0.01 0.0001 0.84 0.01 95.8 0.06
β3 : (X3) 0.60 0.603 0.08 0.0031 3.66 0.08 94.8 0.32 0.604 0.08 0.0037 4.41 0.08 94.3 0.32
λ0 : (Intercept) 0.20 0.194 0.08 -0.0056 -7.34 0.08 96.2 0.30 0.186 0.08 -0.0136 -17.90 0.08 96.1 0.30
λ1 : (X3) -0.10 -0.100 0.11 0.0002 0.19 0.11 94.4 0.42
α0 : (Intercept) -1.20 -1.136 0.08 0.0641 77.06 0.10 82.3 0.29 -1.199 0.07 0.0011 1.62 0.07 95.2 0.28
α1 : (X2) -0.10 -0.102 0.06 -0.0019 -3.11 0.06 94.2 0.24
α2 : (X3) -0.40 -0.404 0.10 -0.0037 -3.68 0.10 94.4 0.38
τ0 : (Intercept) 0.40 0.635 0.04 0.2351 644.84 0.24 0.0 0.06 0.398 0.04 -0.0015 -4.26 0.04 94.8 0.14
τ1 : (X1) 0.10 0.099 0.03 -0.0007 -2.44 0.03 96.4 0.13
τ2 : (X2) -0.10 -0.100 0.01 -0.0002 -1.32 0.01 94.7 0.05
τ3 : (X3) -0.20 -0.200 0.04 -0.0004 -0.89 0.04 95.6 0.18

σω2 0.30 0.289 0.03 -0.0106 -38.36 0.03 91.0 0.11
σ ν ω 0.15 0.151 0.04 0.0011 2.88 0.04 94.2 0.14

-2LogL 41338.5 40326.8

# of converged solutions 999 975
*

Estimated standard errors are based on the distribution of the 999 or 975 parameter estimates from the random-intercept model or mixed-effects location scale model, respectively.