Skip to main content
padlock icon - secure page this page is secure

Free Content Review: analysis of parasite and other skewed counts

Download Article:

You have access to the full text article on a website external to Ingenta Connect.

Please click here to view this article on Wiley Online Library.

You may be required to register and activate access on Wiley Online Library before you can obtain the full text. If you have any queries please visit Wiley Online Library


Objective  To review methods for the statistical analysis of parasite and other skewed count data.

Methods  Statistical methods for skewed count data are described and compared, with reference to a 10‐year period of Tropical Medicine and International Health (TMIH). Two parasitological datasets are used for illustration.

Results  The review of TMIH found 90 articles, of which 89 used descriptive methods and 60 used inferential analysis. A lack of clarity is noted in identifying the measures of location, in particular the Williams and geometric means. The different measures are compared, emphasising the legitimacy of the arithmetic mean for the skewed data. In the published articles, the t test and related methods were often used on untransformed data, which is likely to be invalid. Several approaches to inferential analysis are described, emphasising (1) non‐parametric methods, while noting that they are not simply comparisons of medians, and (2) generalised linear modelling, in particular with the negative binomial distribution. Additional methods, such as the bootstrap, with potential for greater use are described.

Conclusions  Clarity is recommended when describing transformations and measures of location. It is suggested that non‐parametric methods and generalised linear models are likely to be sufficient for most analyses.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Language: English

Document Type: Research Article

Affiliations: London School of Hygiene and Tropical Medicine, London, UK

Publication date: June 1, 2012

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more