a clear trendp = 0.03
There was a clear trend for increasing odds of seropositivity with increasing age: OR 1.6, 95% CI: 1.05–2.40 ( p = 0.03) for 5–14-year-olds and OR 8.13, 95% CI: 2.75–24.1 ( p < 0.001) for ≥15-year-olds compared to horses <5 years old.