A study was conducted to evaluate whether an intensive therapy program reduces the risk of developing retinopathy in patients with diabetes. 2100 diabetes patients aged 13- 39 were enrolled in the...

A study was conducted to evaluate whether an intensive therapy program reduces the
risk of developing retinopathy in patients with diabetes. 2100 diabetes patients aged 13-
39 were enrolled in the two-year study, 1063 patients were randomly assigned to the
intensive therapy group (intervention group), and 1037 patients were randomly assigned
to standard therapy group (control group). This was a two-year study.
In year 1, 32 subjects in the intensive therapy group developed retinopathy, and 43
subjects were withdrawn or lost to follow-up. 97 subjects in the standard therapy group
developed retinopathy, and 38 were withdrawn or lost to follow-up.
In year 2, 26 subjects in the intensive therapy group developed retinopathy, and 30
subjects were withdrawn or lost to follow-up. 89 subjects in the standard therapy group
developed retinopathy, and 33 were withdrawn or lost to follow-up

1. Calculate the incidence rate (per 1,000) for the two-year period for each therapy
group. Assume losses took place and cases were diagnosed at the midpoint of the
period in which they occurred.

2.Calculate and interpret the rate ratio (RR).

3. A Calculate and interpret the percent rate reduction (PRR).