A randomized trial finds that treatment and control group patients taking a new drug had similar cholesterol levels after one year. The drug was thus deemed ineffective. Patients who died during the trial could not have their cholesterol measured. A critic argues that the drug is successful but that this form of attrition has biased the results. Which of these facts would best support his argument?
A. Many patients in the treatment and control groups died during the trial.
B. Many patients with particularly high cholesterol in the treatment and control groups died during the trial.
C. More patients with high cholesterol died in the treatment group than in the control group.
D. More patients with high cholesterol died in the control group than in the treatment group.
Answer: D. More patients with high cholesterol died in the control group than in the treatment group.