Charlson Comorbidity Index (CCI) Calculator

How does this Charlson comorbidity index (CCI) calculator work?

This is a health tool based on the CCI model that assesses the comorbidity risk associated to a series of conditions in order to offer medical specialists an informed decision making process in terms of specific screenings or medical procedures.

The index accounts for the patient age and 16 conditions. This instrument is used to categorize comorbidities of patients and uses the International Classification of Diseases (ICD) diagnosis codes.

The Charlson comorbidity scoring system

The CCI index predicts the ten year mortality for patients presenting one or more of the conditions in the model. This is an index used in decision making when a medical professional is presented with a treatment solution but needs to take into account the short and long term benefits of the treatment in a patient with other comorbidity conditions and should assess their long term risk.

Comorbidity is the term given to the presence of one or more additional conditions existing simultaneously, independently or not (with or without a causal effect) with a disease considered primary. It also suggests the effect of one or more additional conditions on the primary disease.

In this Charlson comorbidity index calculator the age groups and each condition are awarded a specific number of points, some conditions weighing more than others, based on the adjusted risk of mortality. The more points given, the more likely the predicted adverse outcome. The index then sums the points and offers a 10 year survival/ mortality prognosis.

■ Age – divided into five age groups of different risk: age ≤40 years (0 points), age between 41 and 50 (1 point), age between 51 and 60 (2 points), age between 61 and 70 (3 points), 71 years of age or older (4 points).

■ Myocardial Infarction – or acute myocardial infarction (AMI), commonly heart attack, either patient or family history.

■ Congestive Heart Failure – high output cardiac failure, impaired function of the heart leading to blood and oxygen deprivation of the organs.

■ Peripheral Vascular Disease – build up of fatty deposits that restrict the blood supply, usually in the arteries of the limbs, peripheral artery occlusive disease and peripheral obliterative arteriopathy.

■ Cerebrovascular Disease – the group of conditions affecting blood supply to the brain, second most common cause of brain function impairment.

■ Dementia – impaired mental processes with memory loss, thinking, language diminished functions.

■ COPD – Chronic Obstructive Pulmonary Disease with airflow obstructions and a major cause of disability and mortality.

■ Connective Tissue Disease – the group of diseases affecting the bodies connective tissue such as fat, bone or cartilage.

■ Peptic Ulcer Disease – ulceration of the stomach and/ or first part of the small intestine lining.

■ Diabetes Mellitus – the group of metabolic diseases involving high blood sugar levels, not corrected by appropriate insulin levels.

■ Moderate to severe Chronic Kidney Disease – CKD, impaired renal function to different degrees.

■ Hemiplegia – weakness of one entire half side of the body, most often a consequence of stroke.

■ Leukemia – malignancy due to abnormal function of the bone marrow and the other blood forming organs with an increased number of immature and/or abnormal leucocytes.

■ Malignant Lymphoma – cancerous spread in the lymph system.

■ Solid Tumor – abnormal cell mass, either benign or malignant: sarcomas, carcinoma or lymphomas.

■ Liver Disease – hepatic damage either due to alcohol, viral or genetic causes.

■ AIDS – Acquired Immune Deficiency Syndrome caused by the Human Immunodeficiency Virus HIV infection.

CCI interpretation

Each of the conditions listed above are awarded 1, 2, 3 or 6 points depending on the mortality risk associated with each of the comorbidities.

■ 1 point conditions – Myocardial infarction, congestive heart failure, peripheral vascular disease, dementia, cerebrovascular disease, connective tissue disease, ulcer, chronic liver disease, diabetes mellitus.

■ 2 point conditions – Hemiplegia, moderate to severe kidney disease, diabetes mellitus with end organ damage, solid tumor, leukemia, lymphoma.

■ 3 point condition – Moderate to severe liver disease.

■ 6 point conditions – Malignant tumor, metastasis, AIDS.

Calculating the Charlson probability

This is the method through which the CCI score is transformed into a survival/mortality percentage: taking into account that C is the score result obtained by adding the points.

The ten year survival equals 0.983^(e(C*0.9)).

For example, at a score of 6, the ten year survival is 2.25%.

There have been several variations to the index such as the Charlson-Deyo, Charlson-Romano, Charlson-Manitoba and Charlson-D'Hoores comorbidity indices.

References

1) Charlson ME, Pompei P, Ales KL, MacKenzie CR. (1987) A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.J Chronic Dis; 40(5):373-83.

2) Frenkel WJ, Jongerius EJ, Mandjes-van Uitert MJ, van Munster BC, de Rooij SE. (2014) Validation of the Charlson Comorbidity Index in acutely hospitalized elderly adults: a prospective cohort study.J Am Geriatr Soc; 62(2):342-6.

3) Charlson M, Szatrowski TP, Peterson J, Gold J. (1994) Validation of a combined comorbidity index. J Clin Epidemiol; 47(11):1245-51.

4) Chang CM, Yin WY, Wei CK, Wu CC, Su YC, Yu CH, Lee CC. (2016) Adjusted Age-Adjusted Charlson Comorbidity Index Score as a Risk Measure of Perioperative Mortality before Cancer Surgery. PLoS One; 11(2): e0148076.