Reference no: EM132848277

You have been asked to investigate an outbreak of gastroenteritis among patrons of a particular fast food restaurant. Because a) 45 of 65 patrons who reported eating fish there became ill, in contrast to only 5 of 350 patrons who did not eat fish; and b) samples of fish were shown to contain the microorganism believed to be responsible for the gastroenteritis, you infer that consuming the fish was a causal factor in the outbreak. The data below pertain to a second possible etiologic factor, i.e., a history of having eaten French fries ("chips") at that restaurant.

Restaurant food consumed

Fish Chips Ill Total

Yes Yes 29 42

Yes No 16 23

No Yes 2 140

No No 3 210

-What is the crude odds ratio associated with consumption of chips at the restaurant?

-What is that odds ratio adjusted (using the Mantel-Haenszel method) for fish consumption?

-Do you believe having eaten chips contributed to the outbreak? Explain.