ASKING A FOCUSED QUESTION:

PROGNOSIS QUESTIONS

The prognosis of a disease refers to its possible outcomes and the likelihood that each one will occur. Prognosis problems are questions about a patient's future health, life span, and quality of life in the event that s/he chooses a particular treatment option.

EXAMPLE

How do the lifespan and quality of life of an elderly patient undergoing surgery for prostate cancer compared with those for a similar patient who chooses not to undergo the surgery?

In prognosis questions, these issues arise:
  1. What patient characteristics (called "prognosis factors") can predict a patient's eventual outcome?
    • demographic: e.g. age
    • disease-specific: e.g. tumor stage
    • comorbid: other conditions present
  2. Prognostic results are the number of events that occur over time, expressed in:
    • absolute terms: e.g. 5 year survival rate
    • relative terms: e.g. risk from prognostic factor
    • survival curves: cumulative events over time
  3. Was there a representative and well-defined sample of patients at a similar point in the course of the disease?