A matched sample case/control study was performed using cases and controls who have been matched on age and eye color and who all worked for the same chemical company. The cases had been diagnosed with melanoma. The exposure factor being studied was exposure to a chemical. The number of pairs is 80.
|
Controls Exposed
|
Cases Exposed
|
|
|
Yes
|
No
|
Total
|
|
Yes
|
12
|
16
|
28
|
|
No
|
23
|
29
|
52
|
|
Total
|
35
|
45
|
80
|
(a) Compute chi-square for this matched sample case.
(b) Compute the odds ratio and its 95% confidence limit. Write in words what this odds ratio means and what this confidence limit implies.