1.State which of the following studies is more precisethat is, which has a smaller amount of random error:

Study A with a RR of 1.07, 95% CI 0.9-1.8, or Study B with RR of 1.45, 95% CI 0.8-2.5

1. In a cohort study with no loss of follow up, disease status was misclassified as follows:

study Population without Misclassification

2. In a cohort study with no loss to follow-up, disease status was misclassified as follows: Study Population without Misclassification I11 Healthy Exposed 700 3,500 Unexposed 300 4,000 Study Population with Misclassification I11 Healthy Exposed 82: 3,100 Unexposed 200 3,5003 . In a case - control study , exposure status was misclassified as follows Study Population without Misclassification Cases Controls Exposed 700 700 Unexposed 350 900 Study Population with Misclassification Cases Controls Exposed 350 350 Unexposed 700 800