E-Norms: A Method to Extrapolate Reference Values From a Laboratory Population

@article{Jabre2015ENormsAM,
  title={E-Norms: A Method to Extrapolate Reference Values From a Laboratory Population},
  author={Joe F Jabre and Matthew C. Pitt and Jacquie Deeb and Kenneth K. H. Chui},
  journal={Journal of Clinical Neurophysiology},
  year={2015},
  volume={32},
  pages={265–270}
}
Purpose: Collecting reference values in subpopulations such as infants and children can pose a daunting challenge to gather through epidemiologic studies. The authors propose to evaluate a method the authors refer to as extrapolated norms (e-norms) to derive Stimulated Single Fiber EMG jitter reference values from the laboratory data of pediatric and adult cohorts. Single Fiber EMG studies are considered the gold standard test for evaluation of neuromuscular transmission disorders. Methods… 
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29 Citations
Highly Influential Citations
2
Background Citations
5
Methods Citations
10
Results Citations
2

29 Citations

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Citation Type

E‐norms: A method to extract normal values from a laboratory population
TLDR
The scope of the discussion is to limit the scope of this discussion to the difference between the works of Hoffmann and Nandedkar et al., both of which seek to find a variable’s upper limit; and the e-norms method that seeks instead to identify a variable's mean and standard deviation (M SD).
Determining jitter values in the very young by use of the e‐norms methodology
TLDR
In the absence of jitter reference values for the very young, the e‐norms method can be used as an alternative to derive these values from laboratory cohorts.
The extrapolated reference values procedure: Theory, algorithm, and results in patients and control subjects
TLDR
The Extrapolated Reference Values (E‐Ref) procedure extracts RVs from data obtained during clinically indicated EDx testing to develop RVs and was compared with established RVs in several sets of EDx data.
Body Mass Index Changes: An Assessment Of The Effects Of Age And Gender Using The E-Norms Method
TLDR
The e-norms derived range of healthy BMI in adults is from 22.7-30.6, and showed that BMI is consistently higher in men than in women and increases with age, except in subjects aged 80-98 years in whom healthy BMI appears to be lower.
Body mass index changes: an assessment of the effects of age and gender using the e-norms method
TLDR
The authors' e-norms derived healthy BMI ranges agree with traditionally obtained actuarially based methods, supporting the validity and ease of use of the method.
Deriving pediatric nerve conduction normal values in the very young (<3 years)
Facing the challenges of electrodiagnostic studies in the very elderly (>80 years) population
Estimation of reference intervals for transcranial magnetic stimulation: Derived parameters via the hoffman indirect method
TLDR
The authors agree with Nandedkar and colleagues that the derivation of reference intervals from laboratory populations constitutes a useful approach in cases for which published data do not exist, such as in children or when certain variables had not been included in the evaluation of an original control group.
Validating e-norms methodology in ophthalmic biometry
TLDR
The e-norms methodology assisted in establishing a biometric reference range for the biometric data used for intraocular lens power calculation and allowed us to cluster patients into groups based on AL differences.
Assessing neuromuscular junction stability from stimulated EMG in children
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References

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