WHO Global Task Force on TB Impact Measurement: report of a subgroup meeting on methods used by WHO to estimate TB disease burden, 11-12 May 2022, Geneva, Switzerland

Overview

One of WHO’s core functions is monitoring the health situation and health trends.

Each year, WHO publishes estimates of TB disease burden (incidence and mortality) at global, regional and country level, covering the period from 2000 until the latest complete calendar year, in the annual WHO Global TB Report. Estimates of the incidence of drug-resistant TB specifically were added to the report in 2016, with a focus on rifampicin-resistant TB (RR-TB).

Since 2006, estimates of TB disease burden have been produced using standard methods that are periodically reviewed by the WHO Global Task Force on TB Impact Measurement (hereafter, the Task Force).

The Task Force was established in 2006, convened by the TB monitoring, evaluation and strategic information (TME) unit of WHO’s Global TB Programme (GTB). Its initial aim was to ensure a robust, rigorous and consensus-based assessment of whether 2015 TB targets for reductions in TB disease burden (in terms of incidence, prevalence and mortality), set in the context of the United Nations (UN) Millennium Development Goals (MDGs, 2000–2015)) and WHO Stop TB Strategy (2006–2015), were achieved at global, regional and country levels. Its current mission is to ensure robust, rigorous and consensus-based assessment of progress towards milestones and targets for reductions in TB disease burden set in the Sustainable Development Goals (SDGs, 2016–2030) and WHO End TB Strategy (2016–2035), at global, regional and country levels; and to guide, promote and support analysis and use of TB surveillance and survey data for policy, planning and programmatic action. SDG 3 includes a target to “End the TB epidemic” by 2030, with TB incidence (per 100 000 population) defined as the indicator for assessment of progress.

There were two meeting objectives:

1. To present and discuss methods for producing estimates of TB incidence and mortality in 2020–2021 and projections for 2022–2025 that account for the impact of the COVID-19 pandemic.
2. To present and discuss methods for producing estimates of the incidence of drug-resistant TB, with particular attention to new methods for time-series of RR-TB estimates, 2015– 2021.

There were three expected outcomes from the meeting:

1. Proposed methods for producing estimates of TB incidence, TB mortality and RR-TB incidence for publication in the WHO Global TB Report 2022 thoroughly reviewed.
2. Suggestions for improvements to proposed methods for producing estimates of TB incidence and mortality in 2020–2021 and projections for 2022–2025, categorized into a) those which could be implemented in the near-term (by end July 2022) and b) those to be explored in the coming year.
3. Suggestions for how to improve proposed methods for producing estimates of the incidence of RR-TB, categorized into a) those which could be implemented in the nearterm (by end July 2022) and b) those which could be explored in the coming year.