| Group | Characteristics |
| Primary | No functional dependence; negligible comorbidity |
| Intermediate | Dependence in one or more IADLs; stable comorbidity (eg, stable angina, chronic renal insufficiency, etc) |
| Secondary or frail | One of the following criteria: |
| (i) Dependence in one or more ADLS; | |
| (ii) Three or more comorbid conditions or one poorly controlled comorbid condition; | |
| (iii) One or more geriatric syndromes (delirium, dementia, depression, falls, incontinence, spontaneous bone fractures, neglect or abuse, failure to thrive) | |
| Near death |
