Comorbidity (also referred to as polypathology) refers to the number and type of health problems that a patient has. As one would expect, a patient’s health status declines as the number and severity of health problems increase. There are many algorithms for measuring and monitoring comorbidity which address a variety of needs–the most well-known is the Charlson Comorbidity Score. There is often one or more that is suitable for a particular individual or population. In this article, 21 comorbidity calculators from The Medical Algorithms Company are presented in groupings to score comorbidities for general usage, and those that are tied to age, disease, cancer, risk, and drugs.
General Comorbidity Scores
Many comorbidity scores were developed for use in a general population. This allows a single tool to be used for all patients, making it easier to integrate the scores into the medical record and to compare outcomes.
- The General Medical Health Rating (GMHR)
- Adult Comorbidity Evaluation -27 (ACE-27)
- Seattle Index of Comorbidity (SIC)
Charlson Comorbidity Index (CCI)
Probably the most famous of the general comorbidity scores is the Charlson Comorbidity Score. One limitation is that the weighting on some conditions such as AIDS has changed since the score was initially released. Several authors have modified the score to use more recent data to improve performance.
- Charlson Comorbidity Index
- Updated Charlson Comorbidity Index
Age-Related
Comorbidity scores have also been developed to meet specific needs of a specific group. One such group is the elderly, who tend to have more comorbid medical conditions.
- Comorbidity Score of Covinsky
- Modified Comorbidity Index for an Elderly Patient
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Comorbidity Symptom Scale (CmSS)
Unfortunately some children can have significant health problems. The problems faced by this group differ from those seen in the elderly.
- Model for Predicting 1 Year Mortality in Pediatric Patients Based on Comorbid Conditions
Disease-Related
Some diseases may be associated with specific complications that impact the patient more than others. This has resulted in comorbidity scores specific to patients with that disorder.
- Coronary Artery Disease (CAD) Specific Comorbidity Index
- Comorbidity Index for Dialysis Patients
- Comorbidity Scores for Chronic Obstructive Pulmonary Disease (COPD)
Cancer-Related
A subset of disease-related comorbidity scores involves cancer patients. For these patients both the cancer and the comorbid conditions can negatively impact patient outcomes.
- Washington University Head and Neck Comorbidity Index (WUHNCI) for a Patient with Head and Neck Cancer
- Comorbidity Index for a Woman with Breast Cancer
- Simplified Comorbidity Score for a Patient with Non-Small Cell Lung Cancer (NSCLC)
Risk-Related
Some comorbidity scores can be used to identify a patient who is at increased risk for a complication during hospitalization or a procedure.
- Comorbidity Score for Predicting Perioperative Complications
- Chronic Disease Scores (CDS) for Nosocomial Infections
- The Ten Point Comorbidity Index
Drug-Related
Since many significant chronic conditions are treated with medications, the number and type of medications prescribed can give insights into a patient’s condition. The downside is that some conditions are not treated with drugs and so would be missed. The advantage is that prescription data may be readily available in the electronic health record (EHR).
- Comorbidity-Polypharmacy Score (CPS)
- Medication-Based Disease Burden Index (MDBI)
Significance of Comorbidity
Once an appropriate comorbidity score has been selected, it can be used to identify a patient who may:
- Make greater use of healthcare resources
- Have a worse overall survival prognosis
- Have more complications and readmissions
- Have depression and a lower quality of life
- Have a higher risk of falls and accidents
- Risk of Depression in a Diabetic Based on the Number of Comorbid Conditions
Identifying a patient at risk gives an opportunity to mitigate these risks. Surgery may need to be deferred until problems have been brought under control. More aggressive follow-up may be appropriate after hospital discharge in order to reduce readmissions.
Take-Home Message
Medical calculators can help to identify a patient with comorbidity. Tracking comorbidity over time may give insight into a patient’s health status and the ability of the health system to address these problems.
To view a broad range of comorbidity calculators, check out our Medal Pack on comorbidity. This resource can help to obtain valuable insights that can improve outcomes.
