The advance directives decision model. The square node at the left of the diagram is a "choose" node, representing the choice of endorsing a DNI vs. Full Code AD. The circles at the origin of each branch are chance nodes, representing events that may or may not happen with a specified probability. After being admitted to the hospital with an exacerbation patients could be admitted to either the intensive care unit (ICU) or a regular ward (Ward), with non-ventilatory treatment (no NIMV) only offered on the Ward and ETT only in the ICU. Patients who failed mechanical ventilation could opt for no further treatment, (Comfort Measures Only; "CMO"). The triangles at the end of each path (the 'terminal node') represent the health effects associated with the full sequence of events in the path Paths end in death; discharge to either extended care facility for a short term or a long-term; or discharge to home. * ECF discharge is either permanent institutionalization in an ECF (long-term ECF), or temporary institutionalization in an ECF followed by return to home (short-term ECF). Discharge to long-term ECF occurred only in the pathways where there were complications of mechanical ventilation or in patients who survived CMO.