1. Epidemiology and Global Health
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Science Forum: Unit of analysis issues in laboratory-based research

  1. Nick R Parsons Is a corresponding author
  2. M Dawn Teare
  3. Alice J Sitch
  1. University of Warwick, United Kingdom
  2. University of Sheffield, United Kingdom
  3. University of Birmingham, United Kingdom
Feature Article
Cite as: eLife 2018;7:e32486 doi: 10.7554/eLife.32486
2 figures and 3 tables

Figures

A strip plot showing observed lymph node size data by subject (1-12) and sample, after none and a short course of radiotherapy (Short RT).
https://doi.org/10.7554/eLife.32486.004
Boxplots of residuals (observed values - fitted values) for each subject; symbols () are medians, boxes are interquartile ranges (IQR), whiskers extend to 1.5×IQR and symbols () outside these are suspected outliers (a).

Quantile-quantile (Q–Q) plot of the model residuals () on the horizontal axis against theoretical residuals from a Normal distribution on the vertical axis (b).

https://doi.org/10.7554/eLife.32486.005

Tables

Table 1
Variance inflation factors for cluster sizes (m) 2, 5, 10 and 20, and intraclass correlation coefficients (ICC) 0.01, 0.05, 0.1 and 0.5.
https://doi.org/10.7554/eLife.32486.002
mICC
0.010.050.10.5
21.011.051.101.50
51.041.201.403.00
101.091.451.905.50
201.191.952.9010.50
Table 2
Lymph node sizes (mm), by sample slice and subject, by radiotherapy (RT) group, subjects 1 to 6 no RT and subjects 7 to 12 short RT; highlighted cells are those removed to unbalance the design.
https://doi.org/10.7554/eLife.32486.003
NoneShort RT
SubjectSampleSliceSubjectSampleSlice
123123
111.711.981.88712.372.362.20
21.721.981.8522.362.622.60
212.512.552.65811.331.351.15
22.983.202.8021.901.871.85
311.691.721.80911.701.781.78
21.821.971.7322.071.761.85
411.721.782.041012.232.142.21
22.502.652.7722.502.332.16
513.323.273.071112.101.891.75
23.113.033.1122.112.162.12
612.332.482.531212.582.542.59
22.862.872.5222.772.652.60
Table 3
Number of five selected lymph nodes with maximum diameters 2mm, for up to five tissue samples per subject (1-12), after either none or a short course of radiotherapy (Short RT).
https://doi.org/10.7554/eLife.32486.006
NoneShort RT
SubjectSampleSubjectSample
1234512345
144---710000
23452-812---
32332-910102
4241211021402
5344351142433
62553312343--

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