TB Case Detection Rate or TB Treatment Coverage

References in the content below refer to the PBMEF Guide.

Definitions

Percentage of new and relapse tuberculosis (TB) cases and cases with unknown previous TB treatment history (all forms)—that were notified in a reporting year out of the estimated number of TB cases for that year.

Calculation: (Numerator/Denominator) x 100

Numerator

Number of new and relapse TB cases (and cases with unknown previous TB treatment history), all forms (bacteriologically confirmed plus clinically diagnosed, pulmonary and extrapulmonary), that were notified in the reporting period

Denominator

Number of estimated incident TB cases (all forms) in the same reporting period
Ref #
DT-3
Tier Level
Core Indicator
Category
Reach
Type
Core Outcome
Unit of Measure
Percent of cases
Data Type
Percentage
Disaggregations
Age
Gender
Subnational
Reporting Level
National
Reporting Frequency
Annually

The numerator is reported from national TB program official (NTP) records. Quarterly report on TB case registration in the basic management unit.

This indicator is related to incident TB cases; therefore, the following category of patients should not be included in the data reported:

  1. Treatment after failure patients (previously been treated for TB and whose treatment failed at the end of their most recent course of treatment)
  2. Treatment after loss to follow-up patients (previously been treated for TB and were declared lost to follow-up at the end of their most recent course of treatment)
  3. Other previously treated patients

The denominator is available from the current World Health Organization (WHO) Global TB Report for the 30 TB high-burden countries and electronic report of country profile for all countries published on the WHO website. It is an estimation calculated annually based on a mathematical model.

This is a standard WHO indicator. Referring to the WHO database, the variable for the numerator is c_newinc and the variable for the denominator is e_inc_num.

Case-finding is a fundamental principle of effective TB prevention and care. However, one-third of the people who are estimated to fall ill with TB each year are not reached with proper screening, detection, and treatment, or are under-reported. The inability to find and treat the “missing” cases hampers efforts to make further progress in TB care. This indicator measures country-level progress in finding and diagnosing people with TB. Globally, TB detection (i.e., treatment coverage) was 71% in 2019, up from 64% in 2017 and 53% in 2010. Despite increases in TB notifications, there is still a large gap between the estimated number of incident cases and the number of new cases reported due to a combination of under-reporting of detected cases and under diagnosis.

Country national strategic plans for TB set annual targets for the number of TB notifications. This target
will vary by country, but each country should be trying to achieve the End TB Strategy and United Nations High Level Meeting target of 90% or more case detection by 2025 to close the gap between estimated and actual notifications. A high detection rate means more TB patients will be put on treatment and cured, thereby breaking the transmission by undiagnosed infectious TB patients, leading to less TB disease and death in the population.

TB case detection is also used as a planning tool for the NTP. For example, the projections of cases that the NTP plans to detect will help in procuring sufficient TB supplies and ensure that diagnostic services are available to detect more patients.

Reaching all individuals with TB is an important goal for national and global policymakers. The numerator, TB case notification, can be analyzed as a trend over time on its own. However, it is more powerful when compared to the estimated TB incidence to determine the magnitude of the gap between the number of TB cases expected and the TB cases detected.
Trends in TB case detection can be used to monitor progress toward achieving national targets to eliminate TB, assess impact of interventions (e.g., rollout of GeneXpert or active case finding activities), and identify inadequate recording and reporting.

Marked changes in the trend should be reviewed in conjunction with any specific events that may have occurred (e.g., increase/decrease in active case finding, establishment of new diagnostic facilities, expanding TB services through private sector or natural disasters that disrupt TB services) and the impact of other disease outbreaks, like COVID-19.
This indicator, in conjunction with other indicators, especially bacteriologically confirmed cases and treatment success rate, will provide a picture of the cascade of TB care in the country which will help to understand to what extent the TB program is ‘losing’ TB cases along the care pathway. See Appendix 2 for an example of how this indicator is used in the TB pathway and cascade of care. This indicator is limited to the national level only because the denominator is a national-level estimate.

Below are examples (for illustrative purposes only) one can use when presenting this indicator. These charts provide important information but will provide more insight if viewed along with additional contextual information, including age, sex, and key program activities.

Indicator Visualizations