Documenta Ophthalmologica

, Volume 121, Issue 3, pp 215–222 | Cite as

A primer on common statistical errors in clinical ophthalmology

  • Karen HolopigianEmail author
  • Michael Bach


Although biomedical statistics is part of any scientific curriculum, a review of the current scientific literature indicates that statistical data analysis is an area that frequently needs improvement. To address this, we here cover some of the most common problems in statistical analysis, with an emphasis on an intuitive, tutorial approach rather than a rigorous, proof-based one. The topics covered in this manuscript are whether to enter eyes or patients into the analysis, issues related to multiple testing, pitfalls surrounding the correlation coefficient (causation, insensitivity to patterns, range confounding, unsuitability for method comparisons), and when to use standard deviation (SD) versus standard error of the mean (SEM) “antennas” on graphs.


Correlation coefficient Independence Statistics Type I error Variability 



This work was supported by a grant from the Foundation Fighting Blindness, Columbia, Maryland and a grant from the Allene Reuss Memorial Trust, New York, New York.


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Department of OphthalmologyNew York University School of MedicineNew YorkUSA
  2. 2.University Eye HospitalUniversity of FreiburgFreiburgGermany

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