Figure 1. Study Cohorts.

Eligible patients were those whose initial hospital unit after admission was the ward or step-down unit and those who had initially been admitted to a surgical area and whose first postsurgical unit was the ward or step-down unit. Patients with direct admission to the intensive care unit (ICU) were not eligible. (Information about patients who had been admitted to the ICU is provided in Section S3.) Eligible hospitalizations were assigned to the target or nontarget population on the basis of the study definitions. The target population consisted of patients who had a hospitalization in which the patient’s condition reached the alert threshold of the Advance Alert Monitor program. If the alert occurred at a hospital where the program was active, the hospitalization was included in the intervention cohort; if the program was not active at the hospital, the hospitalization was included in the comparison cohort.