Bayesian estimation of the accuracy of the @entity291 respiratory scoring chart and ultrasonography for the diagnosis of XXXX @entity1576 in pre-weaned dairy @entity291 .

@entity1514 @entity358 @entity291 @entity1576
UNASSIGNED: There is currently no gold standard method for the diagnosis of @entity291 @entity1576 (BRD) complex in Holstein pre-weaned dairy @entity291 . Systematic @entity1514 ( @entity1514 ) has been used as a proxy for BRD, but cannot be directly used by producers. The Wisconsin @entity291 respiratory scoring chart (CRSC) is a simpler alternative, but with unknown accuracy. Our objective was to estimate the accuracy of CRSC, while adjusting for the lack of a gold standard. Two cross sectional study populations with a high BRD prevalence (n=106 pre-weaned Holstein @entity291 ) and an average BRD prevalence (n=85 pre-weaned Holstein @entity291 ) from North America were studied. All @entity291 were simultaneously assessed using CRSC (cutoff used >= 5) and @entity1514 (cutoff used >= 1cm of @entity358 ). Bayesian latent class models allowing for conditional dependence were used with informative priors for BRD prevalence and @entity1514 accuracy (sensitivity (Se) and specificity (Sp)) and non-informative priors for CRSC accuracies. Robustness of the model was tested by relaxing priors for prevalence or @entity1514 accuracy. The SeCRSC (95% credible interval (CI)) and SpCRSC were 62.4% (47.9-75.8) and 74.1% (64.9-82.8) respectively. The SeTUS was 79.4% (66.4-90.9) and SpTUS was 93.9% (88.0-97.6). The imperfect accuracy of CRSC and @entity1514 should be taken into account when using those tools to assess BRD status.
