pretest probability

Also found in: Dictionary, Thesaurus, Legal, Financial, Encyclopedia.


(1) The number of people with a specific condition or attribute at a specified time divided by the total number of people in the population.
(2) The number or proportion of cases, events or conditions in a given population.
A term defined in the context of a 4-cell diagnostic matrix (2 X 2 table) as the amount of people with a disease, X, relative to a population.

Veterinary medicine
(1) A clinical estimate of the probability that an animal has a given disease, based on current knowledge (e.g., by history of physical exam) before diagnostic testing.
(2) As defined in a population, the probability at a specific point in time that an animal randomly selected from a group will have a particular condition, which is equivalent to the proportion of individuals in the group that have the disease. Group prevalence is calculated by dividing the number of individuals in a group that have a disease by the total number of individuals in the group at risk of the disease. Prevalence is a good measure of the amount of a chronic, low-mortality disease in a population, but is not of the amount of short duration or high-fatality disease. Prevalence is often established by cross-sectional surveys.

pretest probability

An estimate of a patient's likelihood of illness. It is based on or derived from the prevalence of disease in a community.
See also: probability
References in periodicals archive ?
In patients with a low pretest probability of CAD, the appropriateness of noninvasive imaging remains uncertain.
These savings would occur by reductions in influenza illness and death, reductions in costs related to the investigation and isolation of persons with FRIs, and increases in the pretest probability of SARS and, therefore, the positive predictive value of SARS diagnostic testing.
For example, an Italian patient with a Sardinian background and an MCV of 63 fL has a pretest probability of 12.
The pretest probability of a patient having a PCC/PGL should be carefully considered before testing, because that will help in the interpretation of results and the decision on further action.
John Rumberger of the Mayo Clinic showing increasing cost savings as the pretest probability of heart disease decreases.
If one includes all the patients with ST-elevation myocardial infarction (STEMI) and overt non-STEMI, the pretest probability that an increased cardiac troponin concentration will be associated with ACS is higher than if one includes only patients for whom the diagnosis is unclear.
The mean pretest probability for obstructive coronary artery disease was 24.
Antibodies against synthetic deamidated gliadin peptides as predictors of celiac disease: prospective assessment in an adult population with a high pretest probability of disease.
Useful information for comparing troponin assays includes clinical cohort studies that use chest pain patients in the emergency department, patients with a high pretest probability for unstable angina, and patient populations from the glycoprotein IIb/ IIIa inhibitor trials.
You may want to visit the Internet for an excellent refresher course about concepts such as pretest probability, specificity, etc.
We used ROC curve analysis (8) to estimate the probability of a successful implantation according to urocortin concentration or endometrial thickness and compared the results with the pretest probability, which was defined as the overall pregnancy rate (9).
Obtaining a high-sensitivity D-dimer assay is a reasonable option in appropriately selected patients with low pretest probability of DVT or pulmonary embolism, including younger patients without associated comorbidity or history of VTE and with short duration of symptoms.