Table 1. Summary of conditions and weights used to calculate Charlson comorbidity score^*.

Clinical conditions	Weights
Myocardial infarction, congestive heart failure, peripheral vascular disease, dementia, chronic lung disease, connective tissue disease, ulcer, chronic liver disease	1
Hemiplegia, moderate or severe renal disease, diabetes with complication, tumor, leukemia, lymphoma	2
Moderate or severe liver disease	3
Malignant tumor, metastasis, AIDS	6

^*Weights are assigned to 19 predetermined clinical conditions with the final score being the sum of the weights assigned to the conditions with scores ranging from 0–37. One point for each additional decade of life over 50-years-of-age can be added to initial score to create a single index. The higher the weight total, the greater the likelihood of mortality.