The problem statement poses two research questions: "Does inpatient length of stay differ between patients with and without AKI?" and “How does the likelihood of having AKI change with length of stay?” The three questions below will guide the selection of appropriate statistical methods.
What is the response (Y) of interest and how is it measured? For the first research question, the length of stay is of interest. It is a continuous variable. For the second research question the outcome variable is a diagnosis of AKI, which is a nominal variable.
Are predictor variables mentioned in the problem statement? If so, how many and what are their measurement levels? Outcome (absence or presence of AKI) is in the role of ...