Refers to the presence of one or more additional diseases or disorders co-occurring with a primary disease or disorder.
Comorbidity is each additional disorder or disease.
The additional disorder may be a behavioral or mental disorder.
It describes the effect of all other diseases an individual patient might have other than the primary disease of interest.
The term can indicate either a condition existing simultaneously but independently with another condition or a related medical condition.
Has three definitions:
to indicate a medical condition existing simultaneously but independently with another condition in a patient
to indicate a medical condition in a patient that causes, is caused by, or is otherwise related to another condition in the same patient.
to indicate two or more medical conditions existing simultaneously regardless of their causal relationship..
The Charlson comorbidity index predicts the one-year mortality for a patient who may have a range of comorbid conditions.
Each condition is assigned a score of 1, 2, 3, or 6, depending on the risk of dying associated with each one.
Clinical conditions and associated scores are as follows:
1 each: Myocardial infarct, congestive heart failure, peripheral vascular disease, dementia, cerebrovascular disease, chronic lung disease, connective tissue disease, ulcer, chronic liver disease, diabetes.
2 each: Hemiplegia, moderate or severe kidney disease, diabetes with end organ damage, tumor, leukemia, lymphoma.
3 each: Moderate or severe liver disease.
6 each: Malignant tumor, metastasis, AIDS.
This score is helpful in deciding how aggressively to treat a condition.
The Comorbidity–polypharmacy score consists of the sum of all known comorbid conditions and all associated medications.
In psychiatry comorbidity can reflect our current inability to supply a single diagnosis that accounts for all symptoms.
Comorbidity is widespread among the patients admitted to hospitals, and patients having multiple diseases simultaneously.
In Australian research study of patients having 6 widespread chronic diseases demonstrated that nearly half of the elderly patients with arthritis also had hypertension, 20% had cardiac disorders and 14% had type 2 diabetes, and more than 60% of asthmatic patients complained of concurrent arthritis, 20% complained of cardiac problems and 16% had type 2 diabetes.
In patients with chronic kidney disease the frequency of coronary heart disease is 22% higher and new coronary events 3.4 times higher compared to patients without kidney function disorders.
Nearly 75% of obesity patients have accompanying diseases, which mostly include dyslipidemia, hypertension and type 2 diabetes.
Among young obese patients (from 18 to 29) more than two chronic diseases were found in 22% males and 43% females.
Fibromyalgia is comorbid with several others, including: depression, anxiety, headache, irritable bowel syndrome, chronic fatigue syndrome, systemic lupus erythematosus, rheumatoid arthritis, migraine, and panic disorder.
The number of comorbid diseases increases with age.
Comorbidity increases by up to 80% in people of ages 80 and older.
Patients with idiopathic thrombocytopenic purpura most frequently present are malignant neoplasms, locomotorium disorders, skin and genitourinary system disorders, as well as haemorrhagic complications and other autoimmune diseases.
The survival rate of patients at various stages of cancer differs depending upon the presence or absence of comorbidity.
The development of comorbidity can be due to chronic infections, inflammations, systematic metabolic changes, iatrogenesis, social status, ecology and genetic susceptibility.
Trans-syndromal comorbidity refers to the coexistence, in a single patient, of two and/or more syndromes, pathogenetically related to each other.
Trans-nosological comorbidity refers to coexistence, in a single patient, of two and/or more syndromes, pathogenetically not related to each other.
Can be connected to a singular cause or common mechanisms of pathogenesis of the conditions, which sometimes explaining the similarity in their clinical aspects.
Etiological comorbidity refers to concurrent damage to different organs and systems, which is caused by a singular pathological agent.
Complicated comorbidity: refers to the destabilization of the primary disease and resultant secondary complications.
Iatrogenic comorbidity: appears as a result of negative effect of treatment of the disease.
Primary disease: calls for the foremost necessity for treatment at the time due to threat to the patient’s life and danger of disability.
Primary is the disease, that is the cause of seeking medical help or the reason for the patient’s death.
Methods of evaluating comorbidity:
Cumulative Illness Rating Scale (CIRS): allows a physician calculation of the number and severity of chronic illnesses in the structure of the comorbid state of their patients.
The selected system 0 corresponds to the absence of disorders,
1-Slight (mild) abnormalities or previously suffered disorders.
2-Illness requiring the prescription of medicinal therapy,
3-Disease, which caused disability and
4-Acute organ insufficiency requiring emergency therapy.
The CIRS system evaluates comorbidity in cumulative score, which can be from 0 to 56, with the maximum score is not compatible with life.
Cumulative Illness Rating Scale for Geriatrics (CIRS-G), system takes into account the age of the patient and the peculiarities of the old age disorders.
Comorbidity affects prognosis and increases the chances of fatality.
Comorbidity increases bed days, disability, slows rehabilitation, increases the number of complications after surgery, and increases the chances of decline in aged people.
Comorbidity must be taken into account when treatment plans for any given disease are made.
Comorbidity leads to polypharmacy.