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Table 2 Simulation results when X and Y are normally distributed

From: Standardizing effect size from linear regression models with log-transformed variables for meta-analysis

 

Model A

\( \widehat{Y}=\widehat{\alpha}+\widehat{\beta}\cdotp X \)

Model B

\( \widehat{Y}=\widehat{\alpha}+\widehat{\beta}\cdotp { \log}_b(X) \)

Model C

\( \widehat{{ \log}_a(Y)}=\widehat{\alpha}+\widehat{\beta}\cdotp X \)

Model D

\( \widehat{{ \log}_a(Y)}=\widehat{\alpha}+\widehat{\beta}\cdotp { \log}_b(X) \)

Beta-hat coefficient and standard error from regression model

\( \widehat{\beta} \) = 0.995

se(\( \widehat{\beta} \)) = 0.054

\( \widehat{\beta} \) = 9.587

se(\( \widehat{\beta} \)) = 0.520

\( \widehat{\beta} \) = 0.020

se(\( \widehat{\beta} \)) = 0.001

\( \widehat{\beta} \) = 0.193

se(\( \widehat{\beta} \)) = 0.011

Absolute change in Y for an absolute change of c units in X

Effect size

0.995

0.914

1.006

0.928

95% CI

(0.889–1.101)

(0.817–1.011)

(0.895–1.118)

(0.827–1.029)

Absolute change in Y for a relative change of k times in X

Effect size

0.995

0.914

1.006

0.928

95% CI

(0.889–1.101)

(0.817–1.011)

(0.895–1.118)

(0.827–1.029)

Relative change in Y for an absolute change of c units in X

Effect size

1.0199

1.0183

1.0201

1.0186

95% CI

(1.0178–1.0220)

(1.0163–1.0202)

(1.0179–1.0224)

(1.0165–1.0206)

Relative change in Y for a relative change of k times in X

Effect size

1.0199

1.0183

1.0201

1.0186

95% CI

(1.0178–1.0220)

(1.0163–1.0202)

(1.0179–1.0224)

(1.0165–1.0206)

  1. Note: c = 1 and k = 1.1