The increasing importance of wildlife diseases in conservation efforts places an additional importance on research study design, data analysis, and interpretation. In this paper, we explore the design and analysis of wildlife disease data with regard to hypothesis testing, statistical power, sample sizes, the relative costs of type I versus type II errors, and effect size. To illustrate these ideas, we conducted a literature review of the Journal of Wildlife Diseases (JWD), ran computer simulations that estimate type II error rates for statistical techniques commonly used in JWD, and reanalyzed previously published data on disease prevalence. Many studies published in JWD used chi-squared analysis on prevalence data, but only 19% reported estimates of the observed effect size. Furthermore, 10% of studies had pooled sample sizes ≤40, and many had potentially high costs of type II relative to type I errors. Our computer simulations suggest that many articles published in JWD lack sufficient statistical power, and this, coupled with our findings that many studies often ignore high costs of type II errors, argues for increased attention to statistical power. Finally, our data reanalysis shows how the presentation of observed effect sizes could allow a better assessment of the biologic significance of findings reported in JWD. We conclude with some general guidelines to assist wildlife disease researchers in the design of future studies and the statistical analysis of their data.
Skip Nav Destination
Article navigation
Epidemiology|
July 01 2009
MAKING RELIABLE DECISIONS IN THE STUDY OF WILDLIFE DISEASES: USING HYPOTHESIS TESTS, STATISTICAL POWER, AND OBSERVED EFFECTS
Chris O’Brien;
Chris O’Brien
4
1 School of Natural Resources, University of Arizona, 1311 E. 4th Street, 125 Biological Sciences East, Tucson, Arizona 85721, USA
4 Corresponding author (email: obrienc@email.arizona.edu)
Search for other works by this author on:
Charles van Riper, III;
Charles van Riper, III
2 US Geological Survey, Southwest Biological Science Center, Sonoran Desert Research Station, and School of Natural Resources, University of Arizona, 1311 E. 4th Street, 125 Biological Sciences East, Tucson, Arizona 85721, USA
Search for other works by this author on:
Donald E. Myers
Donald E. Myers
3 Department of Mathematics, University of Arizona, 1311 E. 4th Street, 125 Biological Sciences East, Tucson, Arizona 85721, USA
Search for other works by this author on:
J Wildl Dis (2009) 45 (3): 700–712.
Article history
Received:
February 26 2007
Citation
Chris O’Brien, Charles van Riper, Donald E. Myers; MAKING RELIABLE DECISIONS IN THE STUDY OF WILDLIFE DISEASES: USING HYPOTHESIS TESTS, STATISTICAL POWER, AND OBSERVED EFFECTS. J Wildl Dis 1 July 2009; 45 (3): 700–712. doi: https://doi.org/10.7589/0090-3558-45.3.700
Download citation file:
Citing articles via
Intestinal Parasites in Populations of the Endemic Abyssinian Wattled Ibis (Bostrychia carunculata)
Luis Santiago Cano-Alonso, Bezawork Afework, Jorge Francisco Soares, Hailu Tilahun, Santiago Merino
Oral Rabies Vaccination of Raccoons (Procyon lotor) Across a Development Intensity Gradient in Burlington, Vermont, USA, 2015–2017
Emily M. Beasley, Kathleen M. Nelson, Dennis Slate, Amy T. Gilbert, Frederick E. Pogmore, Richard B. Chipman, Amy J. Davis
Health Assessment of Free-Ranging Eastern Indigo Snakes (Drymarchon couperi) from Hydrologic Restoration Construction Sites in South Florida, USA
James E. Bogan, Jr., Bradley M. O’Hanlon, David A. Steen, Terrence Horan, Robert Taylor, Alexandra K. Mason, Timothy Breen, Holly Andreotta, Bryan Cornelius, April Childress, Michele Elmore
Lymphoproliferative Disease Virus and Reticuloendotheliosis Virus Detection and Disease in Wild Turkeys (Meleagris gallopavo)
Kayla G. Adcock, Roy D. Berghaus, Chloe C. Goodwin, Mark G. Ruder, Michael J. Yabsley, Daniel G. Mead, Nicole M. Nemeth
Migrating Porcupine Quills: Sudden Death of a Yearling American Black Bear (Ursus americanus) at a Wildlife Rehabilitation Center
Florence Coderre, Giselle Kalnins, Rebecca Egan, Sherri Cox