If an analyst wants to compare readmission rates between two hospitals, which hypothesis test is suitable?

The choice of a two-sample Z-test for proportions is appropriate when comparing readmission rates between two hospitals because this test allows analysts to evaluate whether there is a statistically significant difference between the proportions of a binary outcome—in this case, readmission rates—from two independent groups.

In the context of this scenario, the readmission rates at each hospital can be considered as proportions of patients who were readmitted after a certain timeframe. The two-sample Z-test for proportions calculates the difference between these two proportions and assesses whether that difference is statistically significant, taking into account the sample sizes and the variability in each group.

While a one-sample Z-test is used to compare a sample proportion to a known population proportion, it does not help in comparing two different groups directly. The paired t-test measures means from the same group under different conditions, which is not applicable when you are comparing different hospitals. The chi-square test, while useful for categorical data, is typically used when analyzing frequency data or relationships between two categorical variables, but in this specific context of comparing readmission rates that are proportions, the two-sample Z-test is the most suitable choice.