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Understanding the TB Cohort Review Process: Instruction Guide 2006


Adherence to treatment

Following the recommended course of treatment by taking all the prescribed medications for the entire length of time necessary.

Case management

A system in which a specific health department employee is assigned primary responsibility for managing the patient’s case, systematic regular review of patient progress is conducted, and plans are made to address any barriers to adherence.

Cohort review

A systematic review of the management of patients with TB disease and their contacts.  A “cohort” is a group of TB cases counted over a specific period of time, usually 3 months.  TB cases are reviewed for the patient’s clinical status, the adequacy of the medication regimen, treatment adherence or completion, and the results of contact investigation.

Contact investigation

A procedure for interviewing a person who has TB disease to determine who may have been exposed to TB. People who have been exposed to TB are screened for TB infection and disease.


Organisms grown on media (substances containing nutrients) so that they can be identified; a positive culture for M. tuberculosis contains tubercle bacilli, whereas a negative culture contains no detectable tubercle bacilli.

Directly observed therapy (DOT)

A strategy devised to help patients adhere to treatment; means that a health care worker or another designated person watches the TB patient swallow each dose of the prescribed drugs.

Extrapulmonary TB

TB disease that occurs in places other than the lungs, such as the lymph nodes, the pleura, the brain, the kidneys, or the bones; most types of extrapulmonary TB are not infectious.

Multidrug-resistant TB (MDR TB)

TB that is resistant to at least isoniazid and rifampin; more difficult to treat than drug-susceptible TB.

Pulmonary TB

TB disease that occurs in the lungs (about 85% of all U.S. cases), typically causing a cough and resulting in an abnormal CXR; pulmonary TB is usually infectious until adequately treated.

Reported at death

A person with TB disease who was not diagnosed until time of death.

Tuberculin skin test (TST)

A test used to detect TB infection.  Done by using a needle and syringe to inject 0.1 ml of 5 tuberculin units of liquid tuberculin between the layers of the skin (intradermally), usually on the forearm; the reaction to this test, usually a small swollen area (induration), is measured 48–72 hrs after the injection and is classified as positive or negative depending on the size of the reaction and the patient’s risk factors for TB.



Released October 2008
Centers for Disease Control and Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
Division of Tuberculosis Elimination -

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