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Table 1 Bias (SE) for exposures in Group 1 and \({R}^{2}\) with elastic net regression and each LOD accommodation approach compared to using full dataset

From: Accommodating detection limits of multiple exposures in environmental mixture analyses: an overview of statistical approaches

LOD accommodation

Moderate correlation (\(\boldsymbol\sigma\boldsymbol=\mathbf1\boldsymbol/\mathbf2\))

High correlation (\(\boldsymbol\sigma\boldsymbol=\mathbf1\boldsymbol/\mathbf8\))

β1

β2

β3

R2

β1

β2

β3

R2

Scenario 1

 Complete case

-0.12 (0.26)

-0.13 (0.28)

0.02 (0.21)

0.74

-0.16 (0.65)

-0.12 (0.41)

-0.03 (0.42)

0.60

 LOD/\(\sqrt{2}\)

0.03 (0.14)

-0.03 (0.14)

0.01 (0.11)

0.84

-0.03 (0.53)

-0.16 (0.23)

-0.04 (0.22)

0.79

 MI

0.05 (0.14)

0.02 (0.20)

0.02 (0.20)

0.80

0.06 (0.52)

0.12 (0.50)

-0.03 (0.53)

0.82

 Truncated MI

0.00 (0.14)

0.01 (0.15)

0.00 (0.12)

0.83

0.04 (0.52)

0.08 (0.46)

-0.01 (0.40)

0.85

 F-AFT

0.02 (0.14)

0.01 (0.15)

0.00 (0.12)

0.84

0.02 (0.53)

-0.06 (0.41)

-0.01 (0.34)

0.84

Scenario 2A

 Complete case

0.00 (0.26)

 

0.09 (0.22)

0.52

-0.17 (0.65)

 

0.00 (0.40)

0.56

 LOD/\(\sqrt{2}\)

0.14 (0.14)

 

0.10 (0.13)

0.62

-0.01 (0.54)

 

-0.02 (0.21)

0.77

 MI

0.15 (0.15)

 

0.12 (0.20)

0.61

0.09 (0.55)

 

0.05 (0.50)

0.77

 Truncated MI

0.15 (0.15)

0.13 (0.20)

0.61

0.07 (0.54)

 

0.04 (0.48)

0.78

 F-AFT

0.14 (0.14)

 

0.11 (0.14)

0.62

0.03 (0.54)

 

0.01 (0.32)

0.80

Scenario 2B

 Complete case

-0.04 (0.24)

-0.26 (0.26)

0.06 (0.21)

0.64

-0.19 (0.63)

-0.27 (0.14)

-0.01 (0.39)

0.54

 LOD/\(\sqrt{2}\)

0.09 (0.14)

-0.18 (0.17)

0.06 (0.12)

0.73

-0.05 (0.54)

-0.26 (0.12)

-0.02 (0.20)

0.76

 MI

0.10 (0.14)

-0.17 (0.17)

0.06 (0.20)

0.73

0.05 (0.54)

-0.25 (0.14)

0.03 (0.48)

0.76

 Truncated MI

0.09 (0.14)

-0.17 (0.17)

0.07 (0.19)

0.73

0.03 (0.54)

-0.26 (0.13)

0.02 (0.46)

0.78

 F-AFT

0.09 (0.14)

-0.18 (0.17)

0.06 (0.13)

0.74

-0.01 (0.54)

-0.26 (0.13)

0.01 (0.31)

0.80

Scenario 3

 Complete case

-0.10 (0.26)

-0.28 (0.30)

0.01 (0.21)

0.71

-0.17 (0.35)

-0.34 (0.35)

0.02 (0.26)

0.65

 LOD/\(\sqrt{2}\)

0.00 (0.14)

0.13 (0.15)

-0.01 (0.11)

0.85

0.00 (0.14)

0.16 (0.15)

-0.01 (0.11)

0.86

 MI

0.07 (0.15)

-0.03 (0.22)

0.03 (0.20)

0.78

0.07 (0.15)

0.00 (0.25)

0.04 (0.24)

0.77

 Truncated MI

-0.03 (0.14)

0.18 (0.15)

-0.02 (0.12)

0.83

-0.04 (0.14)

0.22 (0.16)

-0.03 (0.12)

0.83

 F-AFT

0.00 (0.14)

0.15 (0.15)

-0.02 (0.12)

0.84

0.00 (0.14)

0.19 (0.16)

-0.03 (0.12)

0.84

Scenario 4

 Complete case

-0.12 (0.26)

-0.10 (0.30)

0.02 (0.22)

0.74

-0.19 (0.32)

-0.18 (0.35)

0.03 (0.28)

0.67

 LOD/\(\sqrt{2}\)

0.00 (0.14)

0.10 (0.15)

0.00 (0.11)

0.86

0.00 (0.13)

0.14 (0.15)

0.00 (0.11)

0.86

 MI

0.04 (0.14)

0.06 (0.22)

0.03 (0.18)

0.81

0.05 (0.14)

0.06 (0.23)

0.03 (0.22)

0.79

 Truncated MI

-0.02 (0.14)

0.12 (0.15)

-0.01 (0.11)

0.84

-0.02 (0.13)

0.15 (0.15)

-0.02 (0.12)

0.84

 F-AFT

0.00 (0.14)

0.12 (0.16)

-0.01 (0.12)

0.85

0.00 (0.13)

0.15 (0.16)

-0.02 (0.12)

0.85

  1. Bias (SE) was reported for exposures in Group 1 (\({\beta }_{1},{\beta }_{2}\) and \({\beta }_{3}\)). All other results are provided in Table S1. All comparisons were made to the parameters with full datasets without LOD. \({R}^{2}\) was calculated by regression \(\widehat{h}\) from each LOD accommodation on \(\widehat{h}\) with the full dataset. In Scenario 2A, \({\beta }_{2}\) was not estimated because \({Z}_{2}\) was not included in the analysis
  2. Abbreviations: Imputation by LOD/\(\sqrt{2}\) (LOD/\(\sqrt{2}\)), MI Conventional multiple imputation, Truncated MI Truncated multiple imputation, F-AFT Imputation by estimates using the AFT model