Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

TB Notes Newsletter

(PDF - 1 MB)

No. 3, 2013


Evaluation of Sputum Culture Conversion in Illinois


The Illinois Department of Public Health (IDPH) Tuberculosis (TB) Control Program serves Illinois, excluding the city of Chicago. The TB program is responsible for statewide TB surveillance, management of the Illinois TB case registry, and oversight of the TB prevention and control activities conducted by local programs. Local programs in Illinois are county or sub-county programs that are independently funded and operated, and they provide direct TB prevention and control services within their jurisdictions.

A goal of the TB program is to ensure all patients are monitored for their response to treatment. One measure of response to treatment is documented conversion of a TB patient’s sputum culture. In 2009, the TB program noted that having incomplete or inaccurate data related to sputum culture conversion was a long-standing problem in Illinois, and it appeared the problem was worsening. The percentage of patients for whom we had documentation of culture conversion within 60 days had been decreasing steadily, from 57.5 percent in 2004 to 37.1 percent in 2008. In addition, in 2008, Illinois implemented a new web-based surveillance system, which may have reduced the speed, completeness, and accuracy of reporting.


The TB Program created an evaluation team in 2009, which consisted of the IDPH TB nurse consultants, the IDPH TB surveillance coordinator, and the TB Nurse at the American Lung Association of Illinois (ALAI), to conduct a program evaluation to fully assess this issue. The evaluation project described here was the evaluation team’s first formal project. The purpose of this evaluation project was to improve patient outcome data by increasing the percentage of sputum culture–positive TB cases with documented culture conversion within 60 days. This project included 1) analysis of data to determine the scope and nature of the problem and 2) exploration of strategies to improve the program’s performance on this indicator of the effectiveness of TB case management, to ensure response to treatment. The primary role of the ALAI nurse was to schedule and facilitate team meetings and assure that the team met its objectives and deadlines.


The evaluation team set the following objectives:

  1. By December 31, 2009, collect data, and by May 31, 2010, analyze data to identify the nature and scope of the problem and identify contributing factors and barriers.
  2. By August 30, 2010, the evaluation team will meet to review the data analysis, and identify and develop strategies to increase documentation of sputum culture conversion within 60 days of treatment initiation.
  3. Increase the percentage of sputum culture positive TB patients with documentation of sputum culture conversion within 60 days to 50 percent by 2015 (national target 61.5 percent).


The surveillance coordinator developed a new electronic report, and the surveillance coordinator and the IDPH TB Nurse Consultant designated as the TB program evaluation focal point analyzed the data. The evaluation team revised the case review form to enhance data collection related to sputum conversion and to include the reason sputum conversion is not reported. Regional nurses reviewed reports and collected data from local programs; for new cases, nurses collected data during case reviews.

Sputum culture conversion data, by county

CountySputum + CasesConvert ≤60 days% Convert ≤60 days

Revised case review form – sputum culture conversion

Revised Case Review Form - Sputum Culture Conversion

The evaluation team held quarterly meetings via conference call. The team developed strategies that included 1) revising the case and cohort review tools, 2) emphasizing sputum culture conversion in case and cohort reviews, 3) consulting with local program staff, 4) providing education about sputum culture conversion at regional meetings, 5) calling local program staff to collect data by telephone, 6) reminding local program staff to collect sputum and document culture conversion, and 7) monitoring surveillance data for completeness on an ongoing basis.

Case or cohort review form

Case or Cohort Review Form


Original data from 2008 cases revealed that one third of patients had a sputum-culture conversion within 60 days, one third in more than 60 days, and one third lacked any documentation. Problems with accuracy of data included documentation of smear rather than culture conversion and use of laboratory result report dates rather than specimen collection dates. In general, counties with the largest numbers of cases and counties with TB clinics had better performance than counties with few cases and counties with all or most cases managed by private healthcare providers.

After the TB nurse consultants provided education for local program staff and implemented the new strategies with case and cohort review, documentation of sputum culture conversion improved.

Percent Sputum Culture Conversion in 60 Days

YearOriginal DataFinal DataNational Target

Local program staff reported better understanding of the reason for documenting sputum culture conversion. Counties with low incidence improved performance from 45 percent to 75 percent in 2009.


Absent, late, or incorrect documentation rather than poor clinical practice or inadequate case management was responsible for the low percentage of cases with sputum-culture conversion within 60 days. Owing to the increased focus on the reporting of sputum culture conversion results generated by the evaluation project, documented performance improved substantially. The activities were completed and the evaluation objectives were met and exceeded more quickly than originally anticipated. It was determined that further progress was unlikely, because of remaining barriers such as delayed sputum culture conversion in patients with extensive disease and limited capacity to enter data more quickly. After consultation with our CDC program and evaluation consultants, the IDPH TB Program decided to change its evaluation focus to a different performance area in 2011.

For more information, contact Carrie Storrs at 217-278-5928 or

—Submitted by Carrie Storrs, RN, MPH, CPH
Illinois Department of Public Health

Top of Page

Contact Us:
  • Centers for Disease Control and Prevention
    Division of Tuberculosis Elimination (DTBE)
    1600 Clifton Rd., NE
    MS E10
    Atlanta, GA 30329
  • 800-CDC-INFO
    TTY: (888) 232-6348
  • Contact CDC–INFO
  • Page last reviewed: November 4, 2013
  • Page last updated: November 4, 2013 The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC-INFO