Prognostication Flashcards
Importance of prognostication
- Provides patients and families with important information to set meaningful goals, priorities, and expectations for care
- Key technical prerequisite for many clinical decisions
- Determines eligibility (prognosis <6 months) for the EI Compassionate Care Benefit and admission to inpatient units in other countries
- Important for design and analysis of clinical trials
Dysfunctional norms of prognostication
- Avoidance
- Wait to be asked, rather than volunteering a prognosis (especially if the clinical situation is atypical)
- Be optimistic (especially if the patient is optimistic)
- Avoid being specific
- Do not use prognostication for survival in treatment decision making
Three components of prognostication
- Formulating the prognosis
- Communicating the prognosis
- Using the prognosis in clinical decision making
How to formulate the prognosis (step 1 of prognostication)
- Clinical prediction of survival
- Use of subjective judgment and formulation of the prognosis by the clinician
- May use a semi-structured approach (median survival, then adjusted for individual factors) - Actuarial judgment
- Uses median survival and hazard ratios
- Performance status is a great predictor (especially palliative performance scale)
- Anorexia-cachexia, dyspnea, and confusion associated with shorter prognosis
Unclear which method is most accurate with prognosis
May give a continuous variable (estimation of number of days, weeks, etc.) or the probability of surviving to a certain point (e.g. % chance of being alive at 6 months)
Prognostic value of PPS
- Average PPS score declines slowly over the 6 months prior to death (starting at approx 70 to 40%)
- More rapid decline in the last month of life
Symptoms associated (and not associated) with prognosis
Predictive of survival
- Self-rated health measures
- Poor mood
- Dyspnea
- Confusion
- Anorexia/cachexia (strongest association)
- Comorbidities (especially in critically ill cancer patients and cancers with a long natural history)
- BNP in CHF
Not predictive
- Pain
- QOL scores
SUPPORT study
- SUPPORT model uses a complex algorithm to give a probability of a patient being alive in 2-6 months time
- In the study used for the basis of the data, only some patients had cancer (limiting utility to palliative care)
- First study to show the potential of using actuarial judgment for prognostication
Palliative Prognostic Index
- Score based on PS, PO intake, dyspnea, delirium, and edema
PPI > 4 predicts death within 6 weeks (PPV 83%, NPV 71%)
Palliative Prognostic Score (PaP)
Score based on:
- Clinical estimation of survival
- KPS
- Dyspnea
- Lymphocyte percentage
- Anorexia
Assigns patients to risk croups with differing probabilities of being alive at 30 days
- Most widely validated, but criticised for exclusion of cognitive function and weight of subjective clinician estimates
Prognostic tools for less seriously ill cancer patients
- No prognostic model for predicting survival from cancer that has been validated in the setting of an outpatient palliative are clinic
- Patients often don’t have many of the cardinal ‘end stage’ disease symptoms and may survive for several years
Prognostic tools for CHF
- Prognosis is actually worse than many cancers
- NYHA classification category is best prognostic marker
- NYHA IV has 1 year mortality of 30-40%
- More accurate predictions of 6-12 month survival more difficult, due to unpredictable disease trajectory and high incidence of sudden death
Prognosis for survival to discharge after CPR
- General hospitalised patient with cardiac arrest, ROSC achieved in 50%, but survival to discharge is less than 20%
NYHA classes
1 - cardiac disease but asymptomatic, no limitations
2 - mild symptoms, slight limitation during ordinary activity
3 - Significant limitation, comfortable only at rest
4 - Severe limitations, symptoms at rest
Prognostication of COPD
Important factors:
- Age
- FEV1
- BMI <21
- Chronic hypercapnia
- Comorbid CV disease
- Declining PS
- History of recent hospitalizations
- Dyspnea (MRC)
Short term prognosis: Severity of acute illness
Long term prognosis: Stage of COPD and comorbidities
Significant variability in prognosis is incomplete understood.
- Can also use the BODE index for prognostication and prediction of risk of hospitalization
On BODE, Points assigned for each of: - BMI
- Obstruction (FEV1 %)
- Dyspnea (MRC dyspnea scale)
- Exercise capacity (6 minute walk distance)
BODE index
- COPD prognostication
Points assigned for each of:
- BMI
- Obstruction (FEV1 %)
- Dyspnea (MRC dyspnea scale)
- Exercise capacity (6 minute walk distance)