The components were taken from:
(1) the Canadian Study of Health and Aging Frailty Index
(2) the Charlson Comorbidity Index
Items:
(1) diabetes mellitus
(2) COPD
(3) congestive heart failure
(4) myocardial infarction
(5) percutaneous coronary intervention (PCI), stenting or angina
(6) hypertension requiring medication
(7) peripheral vascular disease
(8) transient ischemic attack or cerebrovascular accident
(9) cerebrovascular accident with neurological deficit
(10) esophageal varices
(11) ascites
(12) disseminated cancer
Each item was score 0 if absent or 1 if present.
number of items present =
= SUM(points for each item)
comorbidity index =
= (number of items present) / 12
where:
• There are quite a few conditions not included in the item list.
• Esophageal varices and ascites would be surrogate markers for cirrhosis.
• The items are not graded based on severity.
• The index is divided by the number of items assessed. If all 12 items are assessed then the denominator is 12.
Interpretation:
• minimum index: 0
• maximum index: 1
• The higher the index the greater the comorbidity.
Limitations:
• If 1 item is assessed and present, then the index is higher than if 12 items are assessed and 11 are present.
