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Parasitology2007; 134(Pt.14); 2027-2039; doi: 10.1017/S003118200700340X

Statistical approach to measure the efficacy of anthelmintic treatment on horse farms.

Abstract: Resistance to anthelmintics in gastrointestinal nematodes of livestock is a serious problem and appropriate methods are required to identify and quantify resistance. However, quantification and assessment of resistance depend on an accurate measure of treatment efficacy, and current methodologies fail to properly address the issue. The fecal egg count reduction test (FECRT) is the practical gold standard for measuring anthelmintic efficacy on farms, but these types of data are fraught with high variability that greatly impacts the accuracy of inference on efficacy. This paper develops a statistical model to measure, assess, and evaluate the efficacy of the anthelmintic treatment on horse farms as determined by FECRT. Novel robust bootstrap methods are developed to analyse the data and are compared to other suggested methods in the literature in terms of Type I error and power. The results demonstrate that the bootstrap methods have an optimal Type I error rate and high power to detect differences between the presumed and true efficacy without the need to know the true distribution of pre-treatment egg counts. Finally, data from multiple farms are studied and statistical models developed that take into account between-farm variability. Our analysis establishes that if inter-farm variability is not taken into account, misleading conclusions about resistance can be made.
Publication Date: 2007-08-23 PubMed ID: 17714603DOI: 10.1017/S003118200700340XGoogle Scholar: Lookup
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  • Journal Article

Summary

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This research paper presents a new statistical model to measure the effectiveness of anthelmintic treatment in horses using the fecal egg count reduction test (FECRT). The study also highlights the importance of considering inter-farm variability to avoid misleading conclusions about resistance.

Introduction and Background

  • The paper begins by discussing the issue of resistance to anthelmintics in gastrointestinal nematodes in livestock. This is a significant problem that requires suitable methods to identify and quantify.
  • The researchers point out that the quantification and assessment of resistance depend on an accurate measure of treatment efficacy. They highlight a limitation with current methodologies that fail to adequately tackle this issue.

Application of the Fecal Egg Count Reduction Test (FECRT)

  • The study uses FECRT, a widely accepted approach for measuring anthelmintic efficacy on farms. However, the authors also suggest that this method can yield highly variable data that can affect the accuracy of inferences about treatment efficiency.
  • The researchers use novel bootstrap methods to analyze the FECRT data. They develop a statistical model to assess and evaluate the efficacy of anthelmintic treatment on horse farms.

Analysis of the Bootstrap Methods

  • The newly developed bootstrap methods are tested against other methods suggested in past literature. This comparison is primarily done in terms of Type I error (false-positive results) and power (the ability to identify true positives).
  • The results of this analysis suggest that the bootstrap methods maintain an optimal Type I error rate and demonstrate high power to identify differences between presumed and true efficacy. Interestingly, these methods do not require knowledge of the true distribution of pre-treatment egg counts, making them practically applicable.

Consideration of Inter-Farm Variability

  • The paper culminates by examining data from several farms and develops statistical models that accommodate between-farm variability.
  • The researchers find that when inter-farm variability is disregarded, one could arrive at misleading conclusions about resistance. Hence, to more accurately assess anthelmintic response, it is imperative to consider potential differences between farms.

Cite This Article

APA
Vidyashankar AN, Kaplan RM, Chan S. (2007). Statistical approach to measure the efficacy of anthelmintic treatment on horse farms. Parasitology, 134(Pt.14), 2027-2039. https://doi.org/10.1017/S003118200700340X

Publication

ISSN: 0031-1820
NlmUniqueID: 0401121
Country: England
Language: English
Volume: 134
Issue: Pt.14
Pages: 2027-2039

Researcher Affiliations

Vidyashankar, A N
  • Department of Statistical Science, Cornell University Ithaca, NY 14853-4201, USA. anv4@cornell.edu
Kaplan, R M
    Chan, S

      MeSH Terms

      • Animal Husbandry
      • Animals
      • Anthelmintics / administration & dosage
      • Anthelmintics / pharmacology
      • Computer Simulation
      • Drug Administration Schedule
      • Drug Resistance
      • Helminths / drug effects
      • Horse Diseases / parasitology
      • Horse Diseases / prevention & control
      • Horses
      • Models, Biological
      • Parasitic Diseases, Animal / prevention & control

      Citations

      This article has been cited 11 times.
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