Most disease progress in a somewhat predictable manner. Knowledge of the expected disease trajectory is essential for prognostication. Today, let’s talk about the three types of trajectories.

• Trajectory 1: The patient experiences relative wellness followed by a short but predictable period of decline leading to death. Typically associated with cancer diagnoses, and the expected time from terminal diagnosis to death is approximately 6 months without interventions. During the period of decline, the patient may experience symptoms of weight loss, gradual decreased ability to engage in activities of daily living, and a progressive decline in overall condition. Such patients are most likely to access palliative care and hospice services because of the predictability of the disease process.
• Trajectory 2: is characterized by periods of relative well-being punctuated by acute exacerbations that may require hospitalization. After each exacerbations, the patient’s level of overall health declines somewhat, with a clear declinatory pattern discernable over time. This trajectory is associated with chronic illnesses such as heart failure and chronic obstructive pulmonary disease (COPD). The time from terminal diagnosis to death is longer than the process in the first trajectory and may span a period of 2 to 5 years.
• Trajectory 3: is associated with chronic conditions such as dementia, frailty, and debility. Such diseases involved a gradual functional decline over a period of 6 to 8 years without acute exacerbation. However, patients may fall subject to acute illnesses, such as pneumonia or cardiac events, that unexpectedly lead to their death.