How the Charlson Comorbidity Index Is Calculated
The Charlson Comorbidity Index (CCI) is a validated scoring system, developed by Mary Charlson and colleagues in 1987, that predicts long-term mortality risk from a patient's burden of chronic disease. It assigns each of 19 defined comorbid conditions a weight of 1, 2, 3, or 6 points based on that condition's independent association with 1-year mortality, then sums the weights into a single score. A later revision, the age-adjusted CCI (ACCI), adds points for age because age itself independently predicts survival on top of comorbidity. This calculator computes both the unadjusted comorbidity score and the age-adjusted total, plus an estimated 10-year survival probability from the original validation formula.
How the score is calculated
Each selected condition contributes its assigned weight: 1 point each for myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease (stroke or TIA), dementia, chronic pulmonary disease, connective tissue disease, peptic ulcer disease, mild liver disease, and diabetes without complications; 2 points each for hemiplegia/paraplegia, moderate-to-severe kidney disease, diabetes with end-organ damage, any localized tumor, leukemia, and lymphoma; 3 points for moderate-to-severe liver disease; and 6 points each for metastatic solid tumor and AIDS. The age points are added on top: 0 points under age 50, 1 point for 50-59, 2 for 60-69, 3 for 70-79, and 4 for age 80 or older. The estimated 10-year survival probability then applies the formula 0.983e^(score × 0.9) to the age-adjusted total score, where "score" is the combined comorbidity-plus-age total.
Interpreting your score
Higher scores indicate a heavier disease burden and a statistically greater risk of mortality over the studied time horizon. As a general reference, an unadjusted comorbidity score of 0 reflects no listed comorbidities, 1-2 is generally considered a low burden, 3-4 a moderate burden, and 5 or higher a high burden — though these bands are a convenience for interpretation, not a diagnostic cutoff. The index was built and validated on hospitalized patient cohorts, so it performs best as a way to compare relative risk between groups (for example, in research or quality-improvement settings) rather than as a precise individual prognosis.
When to consult a professional
This calculator is an educational tool, not a diagnostic or prognostic instrument for any individual patient. Only a clinician who has reviewed your actual diagnoses, imaging, and lab results can confirm whether a condition meets the "moderate," "severe," or "with complications" thresholds used in the scoring criteria. Use this result to understand how the CCI works and to prepare informed questions for your healthcare provider — not as a substitute for their assessment.