학술논문
Importance of sample size for estimating prevalence: a case example of infectious hematopoietic necrosis viral RNA detection in mixed-stock Fraser River sockeye salmon (Oncorhynchus nerka), British Columbia, Canada.
Document Type
Article
Author
Source
Subject
*SOCKEYE salmon
*FISH mortality
*SAMPLE size (Statistics)
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Language
ISSN
0706-652X
Abstract
Of these freshwater samples,100% (n = 276) of the non-ChilkoNS stock-year combination samples were IHNv-negative, whereas 7.9%(95%CI:4.6%-13.2%)oftheChilkoNSstock-yearcombination samples(n=164)wereIHNv-positive. Two sample-size scenarios exist for prevalence studies in wild salmonids: (i) a priori planning where samples are collected prospectivelytotestprespecifiedquestionsaboutdifferencesintrue and apparent prevalence and (ii) post hoc where samples are either historical or collected for other purposes without precalculated sample sizes, and testing is performed to answer new research questions. Percentage of IHNv-positive Fraser River sockeye salmon samples in target tissues (brain and (or) anterior kidney) categorized by stock group, year, and by location sampled, as well as power calculations to detectadifferencebetweenreferenceapparentprevalenceandsampleapparentprevalenceforeachsamplesize andstock-yearcombination. [Extracted from the article]