Systematic sampling is a probability sampling method where researchers select members of thepopulation at a regular interval (or k) determined in advance12.

In this case, the healthcare quality professional is selecting every other patient admitted to the emergency room, which means the interval k is 2.

This sampling technique is simpler and more straightforward than random sampling, and can cover a wide study area13.

However, it also introduces some potential biases, such as over- or under-representation of certain patterns, depending on the order of the population13.

Therefore, systematic sampling should only be used when the population order is random or random-like, such as alphabetical or numerical12.

If the population order is cyclic or periodic, such as alternating between genders or age groups, systematic sampling may result in a non-representative sample12. References: 1: Dimensions of service quality in healthcare: a systematic review of literature 2: Systematic Sampling | A Step-by-Step Guide with Examples 4: What is systematic sampling? 3: Systematic Sampling: Advantages and Disadvantages