Question

A clinical study is conducted to evaluate the effect of a novel SGLT2 inhibitor on fasting blood glucose levels in patients with type 2 diabetes. The investigators recruit a total of 120 patients and randomly assign them in a 1:1 ratio to either the intervention group ($n = 60$) or the placebo group ($n = 60$). The primary outcome is the absolute change in fasting blood glucose (measured in mg/dL) from baseline to week 12. The data for this outcome are continuous and demonstrate a normal distribution in both groups. The researchers analyze the primary outcome by comparing the mean change between the two distinct groups using an unpaired Student t-test. What is the degrees of freedom associated with the statistical test for this primary analysis?