Final answer:
A case study is an in-depth analysis of a single event, situation, or individual. It involves examining existing sources, conducting interviews, and direct observation. It provides a qualitative understanding of the subject being studied.
Step-by-step explanation:
The analysis being described is a case study, which is an in-depth analysis of a single event, situation, or individual. In this case, the researcher is analyzing the sequential key events of a patient's account of their stay in the intensive care unit (ICU). To conduct a case study, the researcher examines existing sources like documents and archival records, conducts interviews, and engages in direct observation. Case studies are a qualitative research method that allows for a deep understanding of the individuals and the phenomenon being studied.