I’m wondering if you could possibly help me with a little problem.

I have some data:

1. Number and date of disease outbreak each year

2. Date a warning system for this disease occurred each year based on environmental factors.

I would like to get a p value comparing the total amount of outbreaks with warning vs those without.

I do not have enough data to do a complete contingency table I believe, I tried before and my results did not look right.

I would like to assess the probability for each year that the disease would be predicted by the system say 50% of the time, 60%, 70% etc.

EX:

No Warning Warning TOTAL

Outbreaks (Observed) 70 34 104

EXPECTED FREQUENCY 52(50%) 52(50%) 104(Total)

I have been trying different standard Chi Square statistics, but they don’t seem to be working. My p-values get smaller as I increase the expected frequency with a warning. This should not be the case, the probability should be reduced as I impose a higher expected warning compared to what was actually alerted.

If anybody could give me a bit of advice here I would be very grateful, even the name of an analysis which would meet the requirements of what I’m trying to do?

Thank you for your time.

Siobhán