Question: Tight Control of Blood Sugar "Tight glycemic control" means that the blood sugar is kept within a narrow range. Read the abstract below, and then answer the questions that follow it. "Methods: In this two-center, prospective, randomized trial, we enrolled 980 children, 0 to 36 months of age, undergoing surgery with cardiopulmonary bypass. Patients were randomly assigned to either tight glycemic control targeting a blood glucose level of 80 to 110 mg per deciliter or standard care in the cardiac intensive care unit. Results: A total of 444 of the 490 children assigned to tight glycemic control (91%) received insulin versus 9 of 490 children assigned to standard care (2%). Tight glycemic control was not associated with a significantly decreased rate of health care- associated infections (8.6 vs. 9.9 per 1000 patient-days, P = 0.67). Conclusions: Tight glycemic control can be achieved with a low hypoglycemia rate after cardiac surgery in children, but it does not significantly change the infection rate as compared with standard care."
a. Identify the treatment variable and the response variable.
b. Was this a controlled experiment or an observational study? Explain.
c. What does the p-value show?
d. Can you conclude that the use of tight glycemic control affects the rate of infections? Why or why not?