Prognosis ( Greek: πρόγνωσις "fore-knowing, foreseeing") is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) or remain stable over time; expectations of quality of life, such as the ability to carry out daily activities; the potential for complications and associated health issues; and the likelihood of survival (including life expectancy). A prognosis is made on the basis of the normal course of the diagnosed disease, the individual's physical and mental condition, the available treatments, and additional factors. A complete prognosis includes the expected duration, function, and description of the course of the disease, such as progressive decline, intermittent crisis, or sudden, unpredictable crisis. When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because previous research found that this proportion of patients died. This statistical information does not apply to the prognosis for each individual patient, because patient-specific factors can substantially change the expected course of the disease: additional information is needed to determine whether a patient belongs to the 45% who will die, or to the 55% who survive.

Methodology

Disease and prognostic indicators

Prognostic scoring is also used for cancer outcome predictions. A Manchester score is an indicator of prognosis for small-cell

lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, mali ...

. For

Non-Hodgkin lymphoma Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredne ...

, physicians have developed the International Prognostic Index to predict patient outcome. Other medical areas where prognostic indicators are used is in Drug-Induced Liver Injury (DILI) ( Hy's law) and use of an

exercise stress test A cardiac stress test (also referred to as a cardiac diagnostic test, cardiopulmonary exercise test, or abbreviated CPX test) is a cardiological test that measures the heart's ability to respond to external stress in a controlled clinical enviro ...

as a prognostic indicator after

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which ma ...

, also used to indicate

multiple myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, ...

survival rate.

End of life

Studies have found that most doctors are overly optimistic when making a prognosis; they tend to overstate how long a patient might live. For patients who are critically ill, particularly those in an

intensive care unit 220px, Intensive care unit An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensi ...

, there are numerical prognostic scoring systems that are more accurate. The most famous of these is the

APACHE II APACHE II ("Acute Physiology and Chronic Health Evaluation II") is a severity-of-disease classification system, one of several ICU scoring systems. It is applied within 24 hours of admission of a patient to an intensive care unit (ICU): an int ...

scale, which is most accurate when applied in the seven days prior to a patient's predicted death. Knowing the prognosis helps determine whether it makes more sense to attempt certain treatments or to withhold them, and thus plays an important role in end-of-life decisions and advanced care planning.

Estimator

Estimators that are commonly used to describe prognoses include: *'' Progression-free survival'' - the length of time during and after medication or treatment during which the disease being treated (usually cancer) does not get worse. *''

Survival rate Survival rate is a part of survival analysis. It is the proportion of people in a study or treatment group still alive at a given period of time after diagnosis. It is a method of describing prognosis in certain disease conditions, and can be use ...

'' - indicating the percentage of people in a study or treatment group who are alive for a given period of time after diagnosis. *''Survival time'' - the remaining duration of life. If not otherwise specified, it generally starts from the time of diagnosis.

History

One of the earliest written works of medicine is the Book of Prognostics of

Hippocrates Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history o ...

, written around 400 BC. This work opens with the following statement: "It appears to me a most excellent thing for the physician to cultivate Prognosis; for by foreseeing and foretelling, in the presence of the sick, the present, the past, and the future, and explaining the omissions which patients have been guilty of, he will be the more readily believed to be acquainted with the circumstances of the sick; so that men will have confidence to intrust themselves to such a physician." For 19th century physicians, particularly those following the French school of medicine, the main aim of medicine was not to cure disease, but rather to give a

medical diagnosis Medical diagnosis (abbreviated Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information r ...

and achieve a satisfying ''prognosis'' of the patient's chances. Only several decades later did the focus of efforts in Western medicine shift to curing disease.

References

External links

Computer models at prognosis.org
{{Medical terms to describe disease conditions Medical terminology