Module 2: Exercise 3

Table 1: Original data, counts of responses (Yes, Probably, No, Don’t know) and proportion of population exposed

Food item Count (n) Proportion (%)
Yes Probably No Don’t know Yes/
(Yes+No)
(Yes+Prob)/
(Yes+Prob+No)
Lettuce 6 0 0 1 100% 100%
Romaine lettuce 6 0 0 1 100% 100%
Red bell peppers 5 0 0 0 100% 100%
Orange bell peppers 4 0 0 0 100% 100%
Yellow bell peppers 1 0 0 0 100% 100%
Any chicken (including breaded or ground chicken, or chicken burgers, not including deli-meat) 6 1 1 0 75% 88%
Any beef (not including deli-meat) 7 0 1 0 88% 88%
Hamburgers 7 0 1 0 88% 88%
Fresh tomatoes (not grown at home) 5 1 1 0 83% 86%
Bell peppers 5 0 1 1 83% 83%
Mushrooms 5 0 1 1 83% 83%
Did (you/case) handle any eggs (including eggs in their shells or raw or undercooked eggs) in the 7 days prior to illness? 4 1 1 0 80% 83%
Eggs 4 1 1 0 80% 83%
Other prepackaged snack food (e.g., chips, pretzels, crackers, cookies, snack cakes) 4 1 1 0 80% 83%
Strawberries 4 0 1 1 80% 80%
Cherry tomatoes 3 1 1 1 75% 80%
Bananas 4 1 2 0 67% 71%
Whole or cut chicken pieces or parts (e.g., roasts, breasts, wings, thighs, in soups, or as part of a dish, not including deli-meat) 4 0 3 1 71% 71%
Cucumbers 4 0 2 1 67% 67%
Broccoli 4 0 2 1 67% 67%
Ice cream/gelato 4 0 2 1 67% 67%
Cold breakfast cereal 3 1 2 0 60% 67%
Bacon 4 1 3 0 57% 63%

 

Table 2: Exposures with reference values

Food Item Confirmed Cases Reference A† (CDC Food Atlas 2006-2007)  Reference B
(Waterloo Study. Nesbitt et al., 2008)
Reference C
(Foodbook Canada, 2015)
Yes Prob No DK %Y+P
VEGETABLES
Lettuce 6 0 0 1 100.00%  no data 84.00% 82.40%
Romaine 6 0 0 1 100.00% 46.50% no data 48.80%
Bell Peppers 5 0 1 1 83.33%  no data 27.03% 63.60%
Red 5 0 1 1 83.33% 29.50% no data no data
Orange 4 0 1 1 80.00%  no data no data no data
Yellow 1 0 1 1 50.00%  no data no data no data
Tomatoes (fresh, not grown at home) 5 1 1 0 85.71% 59.60% 72.51% 72.90%
Cherry 3 1 1 1 80.00%  no data no data 32.80%
Cucumbers 4 0 2 1 66.67% 46.90% 54.56% 62.90%
Broccoli 4 0 2 1 66.67% 53.30% 43.38% 55.50%
Mushrooms 5 0 1 1 83.33% 33.50% 36.46% 50.00%
MEAT
Any beef (not including deli meat) 7 0 1 0 87.50%  no data 78.65% 78.40%
Hamburgers 7 0 1 0 87.50%  no data 35.88% 39.10%
Bacon 4 1 3 0 62.50% 46.30% no data 27.20%
Any chicken (not including deli meat) 6 1 1 0 87.50% 64.90% 91.43% 85.60%
Whole or cut chicken  pieces or parts 4 0 3 1 57.14%  no data no data 70.00%
DAIRY & EGGS
Ice-cream/gelato 4 0 2 1 66.67% 59.20% 42.82% 42.00%
Eggs 4 1 1 0 83.33% 75.40% 82.22% 80.70%
Did (you/case) handle any eggs (including eggs in their shells or raw or undercooked eggs) in the 7 days prior to illness? 4 1 1 0 83.33%  no data no data no data
FRUIT
Strawberries 4 0 1 1 80.00% 45.00% 31.54% 49.60%
Bananas 4 1 2 0 71.43% 70.30% 79.04% 76.70%
OTHER
Cold breakfast cereal 3 1 2 0 66.67% 69.20% no data 54.30%
Other prepackaged snack food (e.g., chips, pretzels, crackers, cookies, snack cakes) 4 1 1 0 83.33% 71.80%  no data no data

 

Table 3: Binomial probability calculations for exposures and reference populations

Food Item Confirmed Cases Reference A
(CDC Food Atlas, 2006-2007)
Reference B
(Waterloo Study. Nesbitt et al., 2008)
Reference C
(Foodbook Canada, 2015)
Binomial probability
Yes Prob No DK %Y+P Using Reference A Using Reference B Using Reference C
VEGETABLES  
Lettuce 6 0 0 1 100.00% no data  84.00% 82.40% no data 0.3513 0.3130
Romaine 6 0 0 1 100.00% 46.50%  no data 48.80% 0.0101 no data 0.0135
Bell Peppers 5 0 1 1 83.33% no data  27.03% 63.60% no data 0.0063 0.2273
Red 5 0 1 1 83.33% 29.50% no data no data 0.0095 no data no data
Orange 4 0 1 1 80.00% no data   no data no data no data no data no data
Yellow 1 0 1 1 50.00%  no data no data no data no data no data no data
Tomatoes (fresh, not grown at home) 5 1 1 0 85.71% 59.60% 72.51% 72.90% 0.1268 0.2797 0.2847
Cherry 3 1 1 1 80.00% no data  no data 32.80% no data no data 0.0389
Cucumbers 4 0 2 1 66.67% 46.90% 54.56% 62.90% 0.2046 0.2745 0.3232
Broccoli 4 0 2 1 66.67% 53.30% 43.38% 55.50% 0.2640 0.1703 0.2818
Mushrooms 5 0 1 1 83.33% 33.50% 36.46% 50.00% 0.0168 0.0246 0.0938
MEAT  
Any beef (not including deli meat) 7 0 1 0 87.50% no data  78.65% 78.40% no data 0.3180 0.3146
Hamburgers 7 0 1 0 87.50% no data 35.88% 39.10% no data 0.0039 0.0068
Bacon 4 1 3 0 62.50% 46.30% no data 27.20% 0.1845 no data 0.0322
Any chicken (not including deli meat) 6 1 1 0 87.50% 64.90% 91.43% 85.60% 0.1362 0.3662 0.3879
Whole or cut chicken  pieces or parts 4 0 3 1 57.14% no data  no data  70.00% no data no data 0.2269
DAIRY & EGGS  
Ice-cream/gelato 4 0 2 1 66.67% 59.20% 42.82% 42.00% 0.3067 0.1649 0.1570
Eggs 4 1 1 0 83.33% 75.40% 82.22% 80.70% 0.3597 0.4008 0.3963
Did (you/case) handle any eggs (including eggs in their shells or raw or undercooked eggs) in the 7 days prior to illness? 4 1 1 0 83.33% no data  no data no data no data no data no data
FRUIT      
Strawberries 4 0 1 1 80.00% 45.00% 31.54% 49.60% 0.1128 0.0339 0.1525
Bananas 4 1 2 0 71.43% 70.30% 79.04% 76.70% 0.3181 0.2846 0.3026
OTHER      
Cold breakfast cereal 3 1 2 0 66.67% 69.20% no data 54.30% 0.3263 no data 0.2723
Other prepackaged snack food (e.g., chips, pretzels, crackers, cookies, snack cakes) 4 1 1 0 83.33% 71.80% no data no data 0.3229 no data no data