In the course of selecting controls for a study to evaluate the effect of caffeine-containing coffee on the risk of myocardial infarction among women 30-49 years of age, a study noted appreciable differences in coffee consumption among hospital patients admitted for illnesses not known to be related to coffee use. Among potential controls, the coffee consumption of patients who had been admitted to hospital by con- ditions having an acute onset (such as fractures) was compared to that of patients admitted for chronic disorders (Table E1.35).
Cups of Coffee per Day
|
Admission by:
|
0
|
1-4
|
b5
|
Total
|
|
Acute conditions
|
340
|
457
|
183
|
980
|
|
Chronic conditions
|
2440
|
2527
|
868
|
5835
|
(a) Each of the 6815 subjects above is considered as belonging to one of the three groups defined by the number of cups of coffee consumed per day (the three columns). Calculate for each of the three groups the proportion of subjects admitted because of an acute onset. Display these proportions by means of a bar chart.
(b) For those admitted because of their chronic conditions, express their coffee consumption by means of a pie chart.
(c) Calculate the generalized odds and give your interpretation. Exposure is defined as having an acute condition.