Using this tool, we can make useful inferences from small data sets about key properties of disease spread, including the total number and likely position of infected farms. This would provide a clearer picture of any variability in outbreak behaviour over time, whilst reducing reliance on expert opinion or more remote historical precedent. By making the most efficient use of the data available, the tool enabled us to distinguish between different models for disease spread. Our assessment of the tool has found that:
- The tool is accurate approximately 90% of the time, even when as few as about 20 premises have been identified as positive.
- The ability to distinguish between models diminishes as data size decreases. However, by assuming a given model structure based on expert judgement, we can still obtain statistically rigorous prediction of risks even with as few as 6 or 7 premises identified as positive.