OTIS Technical Reference

Online Tuberculosis Information System (OTIS)

Technical Reference

January 2008

Summary: The Online Tuberculosis Information System (OTIS) contains information on verified tuberculosis (TB) cases reported to the Centers for Disease Control and Prevention (CDC) by state health departments, the District of Columbia and Puerto Rico from 1993 through 2006. These data were extracted from the CDC national TB surveillance system. Data for 22 variables are included in the data set and users are able to produce cross-tabulations with multi-level stratification. The data are updated on a regular basis.

Population: All persons reported as TB cases, 1993 through 2006

Source: Online Tuberculosis Information System (OTIS), National Tuberculosis Surveillance System, United States, 1993-2006. U.S. Department of Health and Human Services (US DHHS), Centers for Disease Control and Prevention (CDC), CDC WONDER On-line Database, January 2008.

In WONDER: Users can select criteria to produce cross-tabulated incidence counts. Data are organized into three levels of geographic detail: national, state and Metropolitan Statistical Areas (MSAs)

Introduction

The technical notes provide a detailed description of OTIS--its background, the variables and data limitations--as well as the procedures involved in processing the data. The topics covered include the following:

1. Purpose and Intended Audience of OTIS

2. Assurance of Confidentiality

3. Confidentiality Procedures

4. Introduction to Data

5. Surveillance for TB

a. History of National TB Surveillance Data

b. Case Definition

c. Case Count

d. Report of a Verified Case of TB

e. Completeness and Accuracy of TB Surveillance Data

6. Data Dictionary

a. MSAs with population greater than or equal to 500,000 persons, 1993-2005

b. Description and Coding of Variables Chart

7. Caveats to Use of Data

a. Race/Ethnicity Variable

b. Site of Disease Variable -- Miliary Disease Adjustment

c. Reporting of HIV Infection

d. Completeness of HIV Data

e. Clinical and Treatment Variables -- MDR-TB, COT, DOT

i. Multidrug-Resistant TB (MDR-TB)

ii. Completion of Therapy (COT)

iii. Directly-Observed Therapy (DOT)

8. Determination of Population for Rate Calculation

9. Link to Glossary of TB Terms

10. References

1. Purpose and Intended Audience of OTIS

OTIS provides data on verified cases of TB reported by the 50 states, Washington, D.C. and Puerto Rico health departments to the Centers for Disease Control and Prevention (CDC) Division of TB Elimination (DTBE). These data are intended for a broad audience-- the public, public health practitioners, researchers, and public health officials-- to increase their knowledge of TB and further the use and accessibility of national TB surveillance data. OTIS will enable users to query TB case rates at the national level and TB case counts of demographic, risk factor, clinical, and outcome information at the national, state, and metropolitan statistical area (MSA) levels of geographic detail. In addition, the TB data will help federal, state, and local public health officials design programs, target persons at risk, and provide reliable data for program and policy decisions.

Note: State and local health departments have the most up-to-date and complete data making them the best source for local inquiries; therefore if an OTIS user is interested in further state-specific information, he/she should contact the health department of that particular state. If an OTIS user has any other questions or concerns, he/she can contact the WONDER help desk at cwus@cdc.gov, or call (888) 496-8347.

2. Public Release Disclosure Statement

The data for OTIS contain information abstracted from the national tuberculosis (TB) case report form called the Report of Verified Case of Tuberculosis (RVCT) (OMB No. 0920-0026). These data have been reported voluntarily to CDC by state and local health departments, and are protected under the Assurance of Confidentiality (Sections 306 and 308(d) of the Public Health Service Act, 42 U.S.C. 242k and 242m(d)), which prevents disclosure of any information that could be used to directly or indirectly identify patients. The data on OTIS are being released for public use in accordance with the Assurance and do not identify patients directly, nor do they contain information that can identify patients indirectly. Any effort to determine the identity of any reported cases, or to use the information for any purpose other than statistical reporting and analysis, is a violation of the Assurance. Therefore, users will

· Use the data for statistical reporting and analysis only.

· Make no attempt to learn the identity of any person or establishment included in these data.

· Make no disclosure or other use of the identity of any person or establishment discovered inadvertently, and advise the

Associate Director for Science,

Office of Science Policy and Technology Transfer,

CDC, Mail stop D-50,

1600 Clifton Road, N.E.

Atlanta, Georgia 30333

Phone: 404-639-7240

and the relevant state or public health agency, of such a discovery.

· Data users should not state or imply interpretations of the data analysis are attributable to the Centers for Disease Control and Prevention unless they are collaborating with CDC personnel on the analysis of the data and have written permission from their CDC collaborators to state or imply attribution to CDC.

For more information, see the CDC/ATSDR Policy on Releasing and Sharing Data (at http://www.cdc.gov/od/foia/policies/sharing.htm).

Suggested citation for OTIS data users:

CDC. Online Tuberculosis Information System, National Tuberculosis Surveillance System, United States, 1993-2006. Available at URL http://wonder.cdc.gov/tb.html xxx, date accessed.

3. Confidentiality Procedures

In accordance with CDC guidelines, confidentiality procedures were determined through careful examination of data by DTBE staff and state TB data providers. Aggregation, the grouping of continuous variables into specific intervals, is the main technique used by DTBE to protect the confidentiality of the national TB surveillance data. OTIS users will have the ability to query demographic and risk factor variables at the state and MSA levels for two different time intervals by year of reporting, "previous 5 years" (2001-2006) and “14 years” (all years included in data set, 1993-2006). Cell suppression is applied to count values less than or equal to three (3) at the state and the metropolitan (MSA) level. Cell suppression is not applied at the state level when the cell represents values for the total cases reported by a state within a time period of one or more years. Rates are only available at the national level. Demographic and risk factor variables include the following: Sex; Race/Ethnicity; Country of Birth; Broad Age Groups; Standard Age Groups; HIV Status; Resident of a Long-term Care Facility; Resident of a Correctional Facility; Homeless; Occupation; Injecting Drug Use; Non-injecting Drug Use; Excessive Use of Alcohol. Data for these variables are not available at the state or MSA levels for individual years. However, OTIS users will be able to query single year data for all other variables at all geographic levels.

In addition, the following data is suppressed in respect to the policies of our partners:

· Louisiana HIV data: All HIV data from the state of Louisiana is suppressed when shown at the state or metropolitan (MSA) level. HIV data for Louisiana is included at the national level.

4. Introduction to Data

The Online Tuberculosis Information System (OTIS) contains information reported to the Centers for Disease Control and Prevention (CDC) on verified TB cases in the United States from 1993 through 2006. Individual TB case information is collected at the local and state levels and transmitted electronically to CDC. The reporting areas are funded by DTBE through cooperative agreements to collect individual case data for surveillance purposes. Individual case data are collected using the RVCT form, which contains demographic and diagnostic information, the results of TB drug susceptibility testing, risk factors for TB disease, and treatment outcomes.

5. Surveillance for TB

History of National TB Surveillance Data

TB is a nationally notifiable disease and reporting is mandated by state and local public health law in all states. In 1953, a national surveillance system was established to collect information on cases of active TB. Since 1985, all states report TB cases to CDC using the RVCT. In 1993, DTBE, in conjunction with state and local health departments, implemented an expanded TB surveillance system. As part of the expanded system, a software package, the Surveillance Software for Tuberculosis (SURVS‑TB), was designed and implemented for data entry, analysis, and transmission of case reports to CDC. In 1998, the Tuberculosis Information Management System (TIMS), a windows-based information system, replaced SURVS-TB.

Case Definition

A verified case of TB for public health surveillance may be laboratory confirmed or, in the absence of laboratory confirmation, meet the clinical case definition.¹ The criteria for determining a laboratory confirmed case are 1) isolation of M. tuberculosis from a clinical specimen; 2) demonstration of M. tuberculosis from a clinical specimen by nucleic acid amplification test; or 3) demonstration of acid-fast bacilli in a clinical specimen when a culture has not been or cannot be obtained.

A clinically verified case of TB meets all of the following criteria: 1) a positive tuberculin skin test; 2) other signs or symptoms compatible with TB, such as an abnormal, unstable (worsening or improving) chest x-ray, or clinical evidence of current disease; 3) treatment with two or more antituberculosis medications; and 4) a completed diagnostic evaluation.

For more information, see the Clinical Case Definition document (http://www.cdc.gov/tb/surv/surv2002/PDF/AppendixB.pdf).

Case Count

A case is counted only once within any consecutive 12-month period.² However, a patient who had verified disease in the past is counted again if the case was discharged from supervision (e.g., completed antituberculosis therapy) or lost to supervision for more than 12 months and disease can be verified again. The case is not counted a second time if 12 months have not passed since the case was discharged from supervision. Mycobacterial diseases other than those caused by M. tuberculosis complex are not counted in tuberculosis morbidity statistics unless there is concurrent M. tuberculosis.

CDC's national morbidity reports have traditionally counted all cases; those that meet the standard published case definition and those that are verified by the reporting areas. When the standard case definition is not met, areas are given the option of verifying using other sets of local criteria such as contact to an infectious case or immunosuppression status. In this circumstance, the criteria used to verify the case of TB are categorized as “Provider Diagnosis.”

For more information see Recommendations for Counting Reported Tuberculosis Cases (http://www.cdc.gov/tb/surv/surv2002/PDF/AppendixC.pdf).

Report of a Verified Case of Tuberculosis

From 1985 through 1992 verified cases of TB were reported to CDC using the Report of Verified Case of Tuberculosis (RVCT) form (OMB No. 0920-0026). Some health departments, however, reported cases in the format of the RVCT via magnetic tape, diskette, and/or remote bulletin board. From 1993 to 1997, all data were reported using the expanded RVCT form, entered into SURVS-TB, and transferred to CDC via diskettes. Since 1998, data have been transferred to CDC via TIMS. Identifying information, such as the patient's name, address, and Social Security Number (SSN) are retained at the state and local level. CDC does not receive names, addresses, or SSN of persons reported as TB cases. In the future it is anticipated that RVCT data will be received via the Public Health Information Network (PHIN)/National Electronic Disease Surveillance System (NEDSS).

Completeness and Accuracy of TB Surveillance Data

Formal evaluation of the completeness and accuracy of TB data assists health departments in developing strategies to improve the completeness of reporting, communicate with reporting sources, correct deficiencies in health-care provider knowledge about reporting TB, and improve evaluation of suspect TB cases. Formal evaluations of TB surveillance have found the completeness of reporting of TB cases to state health departments varies a great deal, depending on the type and jurisdiction of the study.³ For example, a 1993-1994 multi-site study found reporting to be greater than 95%⁴, while other studies found ranges of completeness between 40% and 80% depending on the methodology used. ^5-9

Data completeness is essential for producing annual surveillance reports and generating official TB statistics. DTBE takes a number of steps to ensure that the RVCT information received through TIMS from the states is both complete and high quality. Throughout the year, DTBE surveillance staff generate internal reports which include frequencies and cross tabulations on certain variables. The staff then evaluate the data for quality (e.g., do the data make sense and are any conflicting data present) and contact states when inconsistencies exist. States then have the opportunity to review the case and update the data in TIMS. In addition, DTBE finalizes its TB case counts once a year. These data are published in the annual TB surveillance report (http://www.cdc.gov/tb/surv/) and other official publications. As part of the process for finalizing the case count, DTBE staff consider the percentages of data that are unknown or missing, and follow up with states that exceed predetermined levels of data incompleteness that are specific to each variable. If acceptable levels of completeness for risk factors, treatment and clinical variables are not attained, those data will not be published in the annual DTBE surveillance report.

When analyzing OTIS data, consider the following completeness issues:

· New York City risk factor data (with the exception of Resident of a Correctional Facility variable) for 1993 are almost completely unknown.*

· At the national level, risk factor data for most reporting areas have greater than 10 percent missing and unknown for 1993 and 1994 for Resident of Long-term Care Facility and Homeless variables.¹⁰

· At the national level, risk factor data for most reporting areas have greater than 10 percent missing and unknown from 1993 through 1997 for Injecting Drug Use, Non-injecting Drug Use, Excessive Alcohol Use, HIV Status and Occupation.¹⁰

· Completion of therapy data and directly observed therapy data are reported from 1993 through 2004. Because states have up to two years to report these types of data they lag 2 years behind the current report year.

Note: A discussion of the completeness of HIV data is in Section 8.

In addition to the completeness of case reporting, the accuracy of the information collected (e.g., individual elements) on the RVCT is also very important. To date, little research exists on this topic; however, the California Department of Health Services is studying the validity of data collected on the RVCT and has found that most California TB surveillance data have a range of concordance from 18 to 98 percent. For more information about the preliminary findings and recommendations, refer to the abstract referenced.¹¹

6. Data Dictionary

State All 50 states, the District of Columbia, and Puerto Rico

MSA MSAs with a 2006 population greater than or equal to 500,000 persons (See list below.) Metropolitan statistical areas are defined by the federal Office of Management and Budget (OMB). The MSA definitions apply to all areas except the six New England states; for these states, the New England County Metropolitan Areas (NECMAs) are used. Metropolitan areas are named for a central city in the MSA or NECMA, may include several cities and counties, and may cross state boundaries. Further information about MSAs can be found on the U.S. Census Bureau website (http://www.census.gov/population/www/estimates/metro_general/2006/List4.txt). State and MSA data are based on the patient's residence at the time of TB diagnosis.

MSAs greater than or equal to 500,000 population, 2006

Akron, OH	Greenville, SC	Pittsburgh, PA
Albany-Schenectady, NY	Harrisburg, PA	Portland-Biddeford, ME
Albuquerque, NM	Hartford, CT	Portland, OR
Allentown, PA	Honolulu, HI	Poughkeepsie, NY
Atlanta, GA	Houston, TX	Providence, RI
Augusta-Richmond, GA-SC	Indianapolis, IN	Raleigh-Cary, NC
Austin-Round Rock, TX	Jackson, MS	Richmond, VA
Bakersfield, CA	Jacksonville, FL	Riverside-San Bern., CA
Baltimore, MD	Kansas City, MO	Rochester, NY
Baton Rouge, LA	Knoxville, TN	Sacramento, CA
Birmingham-Hoover, AL	Lakeland, FL	St. Louis, MO-IL
Boise City-Nampa, ID	Las Vegas, NV	Salt Lake City, UT
Boston, MA	Little Rock, Ark	San Antonio, TX
Bridgeport, CT	Los Angeles, CA	San Diego, CA
Buffalo, NY	Louisville, KY	San Francisco, CA
Cape Coral, FL	Madison, WI	San Jose, CA
Charleston, SC	McAllen, TX	Sarasota, FL
Charlotte, NC	Memphis, TN	Seattle, WA
Chicago, IL	Miami, FL	Scranton, PA
Cincinnati, OH	Milwaukee, WI	Springfield, MA
Cleveland, OH	Minneapolis-St.Paul, MN	Stockton, CA
Colorado Springs, CO	Modesto, CA	Syracuse, NY
Columbus, OH	Nashville, TN	Tampa-St. Petersburg, FL
Columbia, SC	New Haven, CT	Toledo, OH
Dallas, TX	New Orleans, LA	Tucson, AZ
Dayton, OH	New York, NY	Tulsa, OK
Denver, CO	Oklahoma City, OK	Virginia Beach, VA
Des Moines, IA	Omaha-Council Bluffs, NE-IA	Washington, DC
Detroit, MI	Orlando-Kissimmee, FL	Wichita, KS
El Paso, TX	Oxnard-Ventura, CA	Worchester, MA
Fresno, CA	Palm Bay, FL	Youngstown, OH
Grand Rapids, MI	Philadelphia, PA
Greensboro, NC	Phoenix, AZ

Description and Coding of Variables Chart

Variable definitions can be found in the TIMS User's Guide, Appendix SUR I -RVCT Form Completion Instructions ( ftp://ftp.cdc.gov/pub/software/TIMS/Documentation/Apx%20SUR%20I%20RVCT%20Form%20Completion%20Instructions.pdf).

Variable	Description	Coding Scheme
Criteria Used to Verify a TB Case	Groups cases based on the criteria used to determine which part of the case definition was used to verify cases.	Positive culture result Positive smear/tissue result Clinical case definition Provider diagnosis
Year TB Case Was Counted	Year the case was verified and submitted to the CDC as part of the official case count.	1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
Years Since Arrival in US (Foreign-born only)	For foreign-born cases, the number of years since arrival in the U.S.	<1 year 1- 4 years 5- 14 years ≥ 15 years Unknown
Sex	Biological sex of the patient.	Male Female Unknown
Race/Ethnicity	Calculated by combining race and ethnic origin variables into categories to determine the patient's self-identified racial and ethnic category. Persons of Hispanic origin can be of any race. All other categories are non-Hispanic, single race. In 2003 and 2004, the Asian or Pacific Islander category contains cases among persons who self-reported race as Asian only or Native Hawaiian or other Pacific Islander only. TB cases of multiple race consist of less than 1% of all cases, and for 2003 and 2004 are categorized as Unknown.	White, Non-Hispanic Black, Non-Hispanic Hispanic, All Races American Indian or Alaska Native Asian or Pacific Islander Unknown

Variable

Description

Coding Scheme

Country of Birth

Indicates if patient is U.S. or foreign-born. Foreign-born refers to persons born outside the United States and its possessions and dependencies. Exceptions include persons born overseas to U.S. citizens, on military bases, etc.

U.S.-born
Foreign-born
Unknown

Broad Age Groups

Indicates age group of patient at time of case report. Age groups are based on the patient's age in the month and year the patient was reported to the health department as a suspected case.

0-4 years old
5-14 years old
15-24 years old
25-44 years old
45-64 years old
≥ 65 years old

Unknown

Standard Age Groups (U.S. Census Bureau)

Age group of patient at time of case report. Age groups are based on the patient's age in the month and year the patient was reported to the health department as a suspected case.

<1 years old

1-4 years old

5-14 years old

15-24 years old

25-34 years old

35-44 years old

45-54 years old

55-64 years old

65-74 years old

75-84 years old

≥ 85 years old

Unknown

Vital Status at TB Diagnosis

Indicates whether the patient was alive or dead at the time of diagnosis. Patient is considered dead at diagnosis if deceased at the time the investigation of possible TB was initiated.

Alive at TB diagnosis Dead at TB diagnosis

Unknown

Previous TB Diagnosis

Indicates if this patient has had a previous diagnosis of TB. Previous diagnosis is defined as having had verifiable disease in the past, been discharged (e.g., completed treatment) or lost to supervision for more than 12 consecutive months, and then had verifiable disease again.

Case with previous TB

diagnosis
Case without previous TB

diagnosis
Unknown

Site of Disease (Miliary Adjustment)

[See caveat in Section 7]

Indicates whether the site of disease is pulmonary, extrapulmonary, or both.

Pulmonary only (in lungs)

Extrapulmonary only

(Outside lungs)

Both

Unknown (Includes not stated)

Variable	Description	Coding Scheme
HIV Status [See caveat in Section 7]	Indicates the patient's HIV status, based on published definitions.¹²Status is considered positive if the patient is tested for HIV and the lab result is interpreted as positive based on published criteria, if the patient has a documented history of previous positive HIV test or diagnosis of HIV infection, or this patient gives a history of a previous positive HIV test.	Negative result Positive result Unknown (Includes indeterminate; refused test; test not offered; test done, results unknown; missing)
Resident of Correctional Facility at TB Diagnosis	Indicates whether patient was an inmate of a correctional facility at the time the TB diagnostic evaluation was performed.	No Yes Unknown
Resident of Long-term Care Facility at TB Diagnosis	Indicates whether the patient was a resident of a long-term care facility at the time the TB diagnostic evaluation was performed.	No Yes Unknown
Homeless Within One Year Prior to TB Diagnosis	Indicates whether the patient was homeless at any time within the 12 months prior to diagnosis.	No Yes Unknown
Occupation Within 24 Months Prior to TB Diagnosis	Indicates the occupation of the patient within the 24 months prior to diagnosis.	Health Care Worker Correctional Employee Migratory Agricultural Worker Other Occupation Multiple Occupations Not Employed within Past 24 Months Unknown
Injecting Drug Use Within Year Prior to TB Diagnosis	Indicates whether the patient used an injecting drug within the year prior to diagnosis. Injecting drug use involves use of hypodermic needles and syringes for injection of drugs not prescribed by a physician.	No Yes Unknown
Non-Injecting Drug Use Within Year Prior to TB Diagnosis	Indicates whether the patient used a non-injecting drug within the year prior to diagnosis. Non-injecting drug use involves the use of licensed or prescription drugs or illegal drugs that were not injected and were not prescribed by physician.	No Yes Unknown
Excess Alcohol Use in Year Prior to TB Diagnosis	Indicates whether the patient used alcohol to excess within the 12 months prior to diagnosis.	No Yes Unknown
Multidrug Resistant TB (MDR) [See caveat in Section 7]	Indicates if patient has an initial M. tuberculosis isolate resistant to at least Isoniazid (INH) and Rifampin (RIF).	No Yes Unknown
Directly Observed Therapy (DOT) [See caveat in Section 7]	Indicates whether patient received directly observed therapy, defined as the direct visual observation by a health care provider or other reliable party of the patient's ingestion of medication¹³. Due to reporting treatment-related delays, only data for 1993 to 2003 are available.	Self-administered therapy only Directly observed therapy only Both directly observed and self-administered therapy Unknown
Completion of Therapy ≤ 366 days (COT) [See caveat in Section 7]	Indicates if the patient completed TB therapy in less than or equal to 366 days for patients with “uncomplicated” TB. Due to treatment-related reporting delays, only data for 1993 to 2004 are available.	Displayed as a percentage (not a categorical variable)

7. Caveats to Use of Data

Race/Ethnicity Variable

The 2003 RVCT reflects changes required by the Office of Management and Budget (OMB) for the reporting of race/ethnicity information. The following race categories were first reported in 2003: 1) Multiple Races (2 or more races); 2) Asian-only (Asian or Pacific Islander race reported 1993-2002); and 3) Native Hawaiian or other Pacific Islander.

For 2003 and 2004 data on OTIS, the Asian or other Pacific Islander category contains cases among persons who self-reported race in those years as Asian only or Native Hawaiian or other Pacific Islander only. The “Multiple Races” category consist of less than 1% of all cases, and for the years 2003 and 2004 are categorized as 'Unknown.' For further detail, refer to the annual TB surveillance report (http://www.cdc.gov/tb/surv/).

Site of Disease Variable -- Miliary Disease Adjustment

Miliary disease is classified as both an extrapulmonary and a pulmonary form of TB. In publications prior to 1997, miliary disease was classified as extrapulmonary TB unless pulmonary disease was reported as the major site of TB disease.

Reporting of HIV Infection

The information on HIV status for TB cases is incomplete and data should be interpreted with caution. There are a number of reasons for incomplete reporting of HIV test results to the national TB surveillance system including:

a. concerns about confidentiality of data, which may limit the exchange of data between TB and HIV/AIDS programs;

b. laws and regulations in certain states and local jurisdictions that have been interpreted as prohibiting the HIV/AIDS program from sharing the HIV status of TB patients or from reporting patients with TB and AIDS to the TB program;

c. the voluntary nature of HIV testing, which some TB patients may decline or for those that are tested, may not choose to share the results with their health department; and

d. reluctance by health care providers to report HIV test results to the TB surveillance program staff.

As a result these data may not be representative of all TB patients with HIV infection.

Completeness of HIV data

When analyzing HIV status of TB cases, keep in mind the following limitations:

· All HIV data from the state of Louisiana is suppressed when shown at the state or metropolitan (MSA) level. HIV data for Louisiana is included at the national level.

· California does not report HIV test results to CDC for TB cases. In place of HIV reporting, California reports TB cases which have a co-diagnosis of AIDS, as determined by the presence of an AIDS case report in the state AIDS registry. California performs a TB-AIDS case match on an annual basis after both registries have finalized their case counts for the previous year, and sends the data to CDC. Thus, California is one year behind the current reporting year in reporting HIV data to the national TB surveillance system. California cases listed as HIV-positive in the national TB surveillance system for this time frame include TB cases with a co-diagnosis of AIDS. All other California TB cases have an unknown HIV status.

· The HIV variable, in general, has a high percentage of missing or unknown data. For example, from 1998 through 2000, national HIV results including California showed over 52% missing or unknown. Excluding California, over 42% were missing or unknown during this time.

Clinical and Treatment Variables--MDR, COT & DOT

Multidrug-Resistant TB (MDR-TB)

The case verification criteria and drug susceptibility testing variables collected on the RVCT forms are used to calculate whether a patient has MDR-TB. Patients must have a positive culture and susceptibility testing completed in order to be part of the population (i.e., denominator) for the MDR-TB calculation. If the patient meets these two criteria and has susceptibility results that show resistance to at least the drugs isoniazid and rifampin, he/she is defined as having multidrug-resistant TB. This calculation does not consider resistance to other drugs. Resistance to either isoniazid or rifampin and any other drug, is not defined as MDR-TB.

Completion of Therapy (COT)

Completion of therapy (COT) in OTIS refers to completion of anti-TB drug therapy for an “uncomplicated” patient within 366 days of diagnosis. COT is typically shown as a percentage or proportion of TB cases that complete therapy within 366 days or less and have met several criteria (see detailed criteria in next paragraph). In order to determine whether a case is “uncomplicated”, TB cases are stratified by the indicated length of therapy, based on American Thoracic Society/CDC treatment guidelines^14,15in effect during the period covered, and the patients initial drug susceptibility test results, age, and site of disease. The adequacy of the treatment regimen (e.g., the sufficiency of the duration of therapy, the appropriateness of the prescribed TB drugs) are not part of the calculation of COT. Acquired drug resistance during therapy with the need for a longer duration of therapy is also not considered.

The determination of the indicated length of therapy for 366 days or less is based on a number of factors. Patients with an initial M. tuberculosis isolate resistant to rifampin, patients with meningeal disease and pediatric patients (less than 15 years old) with miliary disease or positive blood culture, require therapy for greater than 366 days a and are therefore not included in the calculations of COT appearing on OTIS. For all other patients, including those with culture-negative disease, those with an unknown culture status, and those with culture-positive disease, but unknown initial drug susceptibility test results, data were included in the calculation of COT for those with 366 days or less of therapy indicated.

The number of cases (i.e., denominator) used to calculate the percentage of those receiving COT includes patients meeting the following criteria: 1) had an indicated length of therapy of 366 days or less, 2) were alive at diagnosis and prescribed an initial regimen of one or more drugs, and 3) did not die during therapy. The percentage of COT was calculated by dividing the number of patients reported as having completed therapy in 366 days or less by the total number of cases in the denominator.

Directly-Observed Therapy (DOT)

Directly-observed therapy status of a patient is reported on the RVCT follow-up report. DOT or supervised therapy involves the direct visual observation by a health care provider or other reliable person of a patient's ingestion of medication. DOT regimens may be administered daily, three times a week, or twice weekly. DOT is currently recommended as the best practice treatment for TB patients by the Centers for Disease Control and Prevention.

8. Determination of Population for Rate Calculations

Rates are expressed as the number of cases reported each calendar year per 100,000 population and are only available in OTIS for national level data. Population denominators used to calculate national and state rates for the years 1993-2006 were obtained from the National Center for Health Statistics bridged-race population counts. Two series were combined: 1) the postcensal 2000-2006 resident population July 1st estimates, based on the Census 2000 counts (release date September 8, 2005); and 2) the intracensal July 1st population estimates for 1990-1999 (release date July 26, 2004). The 1990-1999 estimates were updated to incorporate the bridged-single-race estimates of the April 1, 2000 resident population. The files were prepared under a collaborative arrangement with the U.S. Census Bureau, with support from the National Cancer Institute. See National Center for Health Statistics Population Estimates for more information.

9. Link to Glossary of TB Terms

Refer to the online glossary of Tuberculosis terms ( http://www.cdc.gov/tb/pubs/ssmodules/glos1_5.htm).

10. References

1. Centers for Disease Control and Prevention. Case definitions for infectious conditions under public health surveillance. MMWR 1997;46(No. RR-10):40-41 as referenced in Reported Tuberculosis in the United States, 2002, Appendix B.

2. Centers for Disease Control and Prevention. Recommendations for Counting Reported TB Cases. Atlanta: July 1977 as referenced in Reported Tuberculosis in the United States, 2002, Appendix B.

3. Horsburgh CR, Moore M, Castro KG. Epidemiology of Tuberculosis in the United States. Tuberculosis, Second Edition 2004:31-45.

4. Curtis AB, McCray E, McKenna M, et al. Completeness and timeliness of tuberculosis case reporting: a multistate study. Am J Prev Med 2001;20:108-112.

5. Compos-Outcalt D, England R, Porter B. Reporting of communicable diseases by university physicians. Public Health Rep 1991;106:579-583.

6. Glaser D, Hammersten JE. Pharmacy notification for surveillance and drug utilization review in a metropolitan tuberculosis control program in a low incidence county. Maryland Pharmacist 1978;10:1-3.

7. Weinbaum C, Ruggiero D, Schneider, E, et al. TB reporting. Public Health Rep 1998;113:288.

8. Trepka MJ, Beyer TO, Proctor ME, et al. An evaluation of the completeness of tuberculosis case reporting using hospital billing and laboratory data - Wisconsin, 1995. Ann Epidemiol 1999; 9:419-423.

9. Driver CR, Braden CR, Nieves RL, et al. Completeness of tuberculosis case reporting, San Juan and Caguas regions, Puerto Rico, 1992. Public Health Rep 1996;111:157-161.

10. Centers for Disease Control and Prevention. Reported Tuberculosis in the United States, 2003. Atlanta, GA: U.S. Department of Health and Human Services, 2004.

11. Sprinson J, Lawton E, Flood J, Westenhouse J. Validation of tuberculosis surveillance data in California. Abstract presented at National Tuberculosis Controllers Association Conference, Atlanta, Georgia, June 2002.

12. Centers for Disease Control and Prevention. Interpretation and use of the Western Blot Assay for serodiagnosis of human immunodeficiency virus type 1 infections. MMWR 1989;38 (No. S-7): 1-7.

13. American Thoracic Society. Control of Tuberculosis in the United States. Am Rev Respir Dis 1992;146:1623-1633.

14. American Thoracic Society/Centers for Disease Control and Prevention. Treatment of tuberculosis. Am J Respir Crit Care Med 2003;167:603-62.

15. American Thoracic Society/Centers for Disease Control and Prevention. Treatment of tuberculosis and tuberculosis infection in adults and children. Am J Respir Crit Care Med 1994;149:1359‑74.

* Risk factor variables for TB included in OTIS are Injecting Drug Use; Non-injecting Drug Use; Homelessness, Excessive Alcohol Use; Resident of Long-term Care Facility; Resident of a Correctional Facility; Occupation; and HIV status.