You are given results on a case control study on alcoholism and breast cancer, 200m participants with Breast cancer and 200 participants without cancer were selected and questioned on previous alcohol use.

Breast Cancer (+)

Breast Cancer (-)

Total

Heavy alcohol use

40

20

60

No/low alcohol use

160

180

340

total

200

200

400

1. Calculate and interpret the appropriate measure of association for this study?
2. You later learn that 15 of the controls [Breast CANCER (-)] did not remember their previous heavy alcohol use and incorrectly reported that they were low alcohol users. By comparison all the breast cancer (+) cases correctly remembered their alcohol use. Please compare appropriate measure of association. HINT new 2x2 table below)Was there evidence of Bias in this study? If so what type of Bias?