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Table 2 Methods used for comparing

From: Evaluation of regression methods when immunological measurements are constrained by detection limits

Methods

Description

Software

Disadvantage

Deletion

Remove NDs.

Any statistical package

Bias

DL/2

Substitute each ND with half of the value of DL.

Any statistical package

Large RMSE for large proportion of NDs

ROS

After computing a linear regression for data versus their normalized scores below-DL values are extrapolated under distributional assumption.

R-package NADA [24, 27]

Underestimation of variance for large proportion of NDs

MI

Estimation of mean and standard deviation by MLE. Creating 10 complete samples. Pool the results from 10 individual analyses.

R (software available on request)

Bias for small proportion of NDs

TOBIT

Parametric estimation method for incorporating NDs.

R, Stata [28], SAS [29]

Sensitive to heteroscedastic errors

LOGIT

Create binary dependent variable of NDs (0s) and detects (1s).

Any statistical package

Loss of information & parameter estimates are less interpretable