Skip to content
OrthoMeasure

Clinical calculator

CCI Calculator

Charlson Comorbidity Index

The Charlson Comorbidity Index is a weighted checklist of 16 comorbid conditions that produces a comorbidity score of 0 to 33, to which up to 4 points are added for age, and which estimates 10-year survival at roughly 98% for a total of 0, 90% for 2, 53% for 4 and 21% for 5.

No licence required17 items~3 min0–37, lower is better

Cardiovascular

Mark each condition that the patient carries as an established diagnosis, not as a suspicion.

1Myocardial infarction

A documented infarction, whether or not it caused persisting symptoms. Angina alone does not count.

2Congestive heart failure

Symptomatic heart failure that has responded to, or required, treatment.

3Peripheral vascular disease

Intermittent claudication, prior bypass or angioplasty for arterial insufficiency, gangrene, acute arterial insufficiency, or an untreated aortic aneurysm of 6 cm or more.

4Cerebrovascular disease

A stroke with no or minimal residual deficit, or a transient ischaemic attack.

Neurological

5Dementia

Chronic cognitive deficit documented on history and examination.

6Hemiplegia or paraplegia

Established motor deficit from stroke or spinal cord injury. Scored instead of, not in addition to, the milder cerebrovascular category where both apply.

Respiratory, gastrointestinal, metabolic and renal

7Chronic pulmonary disease

Symptomatic chronic lung disease, including COPD and asthma requiring regular treatment.

8Connective tissue disease

Rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, polymyositis or polymyalgia rheumatica.

9Peptic ulcer disease

Any ulcer that has required treatment, including bleeding ulcers.

10Liver disease

Grade by the presence of portal hypertension — that is the dividing line between the 1-point and 3-point categories.

11Diabetes mellitus

End-organ damage means retinopathy, neuropathy or nephropathy. Diet-controlled diabetes alone was scored 0 in the original index.

12Renal disease

Malignancy and immune status

Solid tumours, leukaemia and lymphoma count only if treated within the last five years.

13Solid tumour

A tumour treated more than five years ago and in remission scores 0. Metastatic disease supersedes the localised category rather than adding to it.

14Leukaemia

Acute or chronic leukaemia, including polycythaemia vera, treated within the last five years.

15Lymphoma

Hodgkin and non-Hodgkin lymphoma, multiple myeloma and Waldenström macroglobulinaemia, treated within the last five years.

16AIDS

AIDS-defining illness. Asymptomatic HIV infection was not scored in the original index, and modern antiretroviral therapy has made this the least transferable of the original weights.

Age

Age is optional. Entering it produces the combined age–comorbidity index, which is the form used in most published orthopaedic work.

Under 50 adds nothing; 50–59 adds 1 point, 60–69 adds 2, 70–79 adds 3, and 80 or over adds 4.

years

What the CCI score means

CCI scores run from 0 to 37, where a lower score is better. The bands below are conventional reporting categories, not diagnostic cut-offs.

  • No comorbidity0–0

    One-year mortality was 12% in the original cohort of 559 medical inpatients.

  • Mild comorbidity1–2

    One-year mortality was 26% in the original cohort of 559 medical inpatients.

  • Moderate comorbidity3–4

    One-year mortality was 52% in the original cohort of 559 medical inpatients.

  • Severe comorbidity5–33

    One-year mortality was 85% in the original cohort of 559 medical inpatients.

Published criteria and reliability

The published cut-offs that define this instrument, and the measured agreement between observers using it. Each is reported with the population it was derived in.

TypeValueSubscalePopulationFollow-upSource
CriterionScore 0 – 12% one-year mortality—559 medical inpatients, comorbidity component before age adjustment1 yearCharlson ME 1987
CriterionScore 1–2 – 26% one-year mortality—559 medical inpatients, comorbidity component before age adjustment1 yearCharlson ME 1987
CriterionScore 3–4 – 52% one-year mortality—559 medical inpatients, comorbidity component before age adjustment1 yearCharlson ME 1987
CriterionScore 5 or more – 85% one-year mortality—559 medical inpatients, comorbidity component before age adjustment1 yearCharlson ME 1987
CriterionEstimated 10-year survival: 98% at 0, 96% at 1, 90% at 2, 77% at 3, 53% at 4, 21% at 5—685 breast cancer patients treated in the 1980s10 yearsCharlson ME 1987
CriterionEach additional point raised the relative risk of death by roughly 1.5 in the derivation cohort—Medical inpatients1 yearCharlson ME 1987
CriterionHigher index scores independently associated with adverse events and 30-day readmission after orthopaedic surgery—Orthopaedic surgical patients30 daysVoskuijl T 2014

Criterion is a published cut-off, definition or performance figure belonging to a classification or decision rule — it is not a change score and should not be read as one.

How the score is calculated

Stated in full so the calculation can be independently checked, and reproduced by hand if needed.

Each comorbidity present contributes its published weight. One point each for myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, connective tissue disease, peptic ulcer disease, mild liver disease and uncomplicated diabetes. Two points each for hemiplegia, moderate or severe renal disease, diabetes with end-organ damage, a localised solid tumour treated within five years, leukaemia and lymphoma. Three points for moderate or severe liver disease. Six points for metastatic solid tumour and for AIDS. The graded categories are mutually exclusive — a patient scores either mild or severe liver disease, either uncomplicated or complicated diabetes, and either a localised or a metastatic tumour — so the attainable comorbidity total is 0 to 33; adding both grades of a graded category, which is the usual implementation error, would inflate that ceiling by a further four points. Age adds one point per decade from 50: 0 under 50, 1 for 50–59, 2 for 60–69, 3 for 70–79 and 4 for 80 and over, giving a reported combined total of 0 to 37. Estimated 10-year survival is then calculated from the combined total as 0.983 raised to the power of e raised to the power of (total score × 0.9), expressed as a percentage. The severity band reported with the result is matched against the comorbidity component alone, not against the combined total, because the one-year mortality strata it carries were derived in 1987 from the comorbidity score before the age adjustment existed.

Missing data

A comorbidity category left unmarked is counted as absent, which is how the index is applied in practice — it is a presence checklist, not a questionnaire with a missing-value rule. Because of that, an incompletely marked form returns a score that can only be an underestimate, and the result says so. Age is optional; if it is omitted, the unadjusted comorbidity score is reported and the survival estimate is calculated from it.

Instrument profile

Developer
Mary E. Charlson and colleagues
Institution
New York Hospital–Cornell Medical Center, New York
First published
1987
Items
17
Response format
16 weighted comorbidity categories plus age in years
Score range
0 to 37
Direction
Lower score = better
Recall period
Lifetime history of diagnosed comorbidity. Solid tumour, leukaemia and lymphoma count only if treated within the preceding five years.
Completion time
About 3 minutes
Age range
Adults; the age adjustment is defined from 50 years upward
Regions
General Health
Conditions
Multimorbidity, Perioperative risk stratification, Hip fracture, Osteoarthritis, Periprosthetic joint infection
Procedures
Total hip arthroplasty, Total knee arthroplasty, Hip fracture surgery, Spinal fusion, Revision arthroplasty
Observer agreement
Agreement between independent chart abstractors is generally good, and agreement between chart-derived and ICD-derived scores is moderate to good.
Validity
Predicts one-year and ten-year mortality in the derivation cohorts and has been validated in surgical, oncological and dialysis populations. The ICD-coded adaptations (Deyo 1992, Quan 2005, Quan 2011) show discrimination for in-hospital mortality broadly in the 0.75–0.85 range as a c-statistic across large administrative datasets.
Reliability
Not a change measure. It is a baseline risk descriptor and is not expected to move with treatment.
Ceiling effect
No meaningful ceiling in clinical practice — scores above about 8 are rare, and the survival formula collapses to near zero there, which overstates the true risk.
Floor effect
Marked floor effect in elective orthopaedic populations, where most patients score 0 and the index cannot separate them. The Elixhauser measure and frailty indices discriminate better in that setting.

Normative values

Reference values from published cohorts, for comparison against the score you calculated.

PopulationAgeMeanSD
Elective primary total hip and knee arthroplasty cohorts—Strongly skewed to 0 – the majority of elective arthroplasty patients carry no scored comorbidity, which is why the index discriminates poorly in this group—
Hip fracture and revision arthroplasty cohorts—Substantially higher and more dispersed than elective primary arthroplasty, driven largely by the age adjustment—

When to use the CCI

Well suited to

  • Risk-adjusting outcomes between cohorts in orthopaedic registry and database research, where it is the most widely reported comorbidity measure and makes results comparable with the existing literature.
  • Framing a discussion about life expectancy when choosing between a durable and a salvage procedure, for example fixation versus arthroplasty in an older patient with a femoral neck fracture.
  • Case-mix adjustment where only a small number of variables can be carried, since a single weighted number captures most of the comorbidity signal.

Limitations and poor fits

  • As an individual prognostic statement. The survival formula comes from a 1980s cohort, and the AIDS and malignancy weights in particular no longer reflect contemporary treatment.
  • To separate patients within an elective primary arthroplasty population, where the floor effect leaves most of them at 0.
  • As a substitute for a functional or frailty assessment — the index says nothing about mobility, nutrition, cognition or social support, all of which drive orthopaedic outcome independently.
  • Where the data source is an administrative dataset without a present-on-admission flag, since complications of the index admission will be miscounted as comorbidity.

CCI compared with other instruments

Instruments measuring a related construct, with the practical difference between them.

InstrumentItemsRangeWhat it adds
Elixhauser21-19–89The Elixhauser comorbidity score applies the van Walraven point weights to 30 comorbidities, giving each a whole-number weight from −7 to +12 so that their sum predicts in-hospital death from hospital diagnosis codes — and in one large national inpatient dataset it discriminated slightly better than the Charlson index.
ASA21–6The ASA Physical Status Classification grades a patient’s pre-operative systemic health from I, a normal healthy patient, to VI, a declared brain-dead organ donor, with an E modifier added for emergency procedures.
ECOG10–5The ECOG Performance Status grades a patient’s functional capacity from 0, fully active, to 4, completely disabled and confined to bed or chair, with 5 denoting death — and in orthopaedic oncology it is the single figure that most often decides whether a metastatic lesion is worth fixing.

Copyright and permitted use

Published openly because it is the question every clinician and researcher asks before using an instrument, and almost nobody answers it.

No licence required

A published weighting method rather than a copyrighted questionnaire. The weights, the age adjustment and the survival formula appear in full in the source papers, and the ICD-9-CM and ICD-10 coding algorithms (Deyo, Romano, Quan) are published openly. No licence is required.

References

  1. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. Journal of Chronic Diseases. 1987.doi:10.1016/0021-9681(87)90171-8PMID 3558716
  2. Charlson M, Szatrowski TP, Peterson J, Gold J. Validation of a combined comorbidity index. Journal of Clinical Epidemiology. 1994.
  3. Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. Journal of Clinical Epidemiology. 1992.PMID 1607900
  4. Quan H, Sundararajan V, Halfon P, et al.. Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Medical Care. 2005.PMID 16224307
  5. Quan H, Li B, Couris CM, et al.. Updating and validating the Charlson comorbidity index and score for risk adjustment in hospital discharge abstracts using data from 6 countries. American Journal of Epidemiology. 2011.PMID 21330339
  6. Voskuijl T, Hageman M, Ring D. Higher Charlson Comorbidity Index scores are associated with readmission after orthopaedic surgery. Clinical Orthopaedics and Related Research. 2014.

Editorial status

This page has not yet been signed off by a named clinical reviewer. The scoring logic is stated in full above so it can be independently verified, and every threshold is traceable to its source. See our editorial methodology.