Measuring TB incidence prevalence and mortality an overview

Measuring TB incidence, prevalence and mortality: an overview of the recommendations of the WHO Global Task Force on TB Impact Measurement Ana Bierrenbach WHO /STB / TME bierrenbacha@who. int http: //www. who. int/tb/advisory_bodies/impact_measurement_taskforce/en/index. html

Mandate l To produce a robust, rigorous and widely-endorsed assessment of whether the 2015 targets for reductions in TB incidence, prevalence and mortality are achieved at global level, for each WHO Region and in individual countries l To regularly report on progress towards these targets in the years leading up to 2015 l To strengthen national capacity in monitoring and evaluation of TB control

3 strategic areas of work § Use of routine surveillance data to measure incidence, prevalence and mortality (all countries) § Prevalence of TB disease surveys in at least 21 global focus countries § Periodic review and revision of methods used to translate data from surveillance systems and surveys into estimates of disease burden

Framework for systematic assessment of surveillance data Data Quality Reports completed No dups, no misclassifications Consistency of data Accuracy/completeness VR Changes over time Trends Incidence and Mortality IMPROVE surveillance system Time-changes in notifications Changes in case-finding Changes in TB determinants Trends in notifications reflect trends in incidence Inventory studies capture re-capture "onion" model VR data UPDATED estimates notifications ≈ incidence VR mortality data ≈ deaths CERTIFIED

Progress in applying framework in 2009 4 regional workshops (red) with > 50 countries, 3 country missions (blue) NB highlighted the necessity of electronic recording and reporting

An example from Tanzania: updated estimates of TB incidence from 1995 to 2007

Recommendations for strengthening surveillance and related estimates of disease burden l l l l Need to revise TB/HIV dedicated form → more data on HIV status by case type available, easier to separate effect of incidence and case-finding efforts on notifications Reconstruct historical data at district level – much data available that cannot yet be used Record treatment outcome by HIV status Strengthen capacity to analyse surveillance data, initially at national level Make greater use of surveillance data to help identify where and how programme performance can be improved→ policy change Feed back results of data analysis to lower administrative levels Strengthen supervision at all levels: M&E, lab, …

The 21 global focus countries for TB disease prevalence surveys Asian countries on track, African countries not

Criteria used to identify 21 global focus countries Groups Estimated Prevalence SS+ TB (per 100, 000 pop) Share of global burden SS+ TB Estimate HIV prevalence adults Baselines survey already done 1 ≥ 100 ≥ 1% - - 2 ≥ 70 ≥ 1% - 3 ≥ 200 ≥ 0. 5% - - 4 - - - yes

Updated methods n Three Task Force meetings n Major outcomes n Systematic documentation of uncertainty n Reassessment of trends based on systematic analysis of surveillance and programmatic data n Systematic documentation of expert opinion and how this has been used n Simplification of models n Better use of mortality data

Where to find more information about the Task Force recommendations l Lancet review article published on methods for measuring TB incidence, prevalence and mortality (Jan '08) l Policy paper building on Lancet review (Sep 08, finalized '09) l Web site (Sep '09) http: //www. who. int/tb/advisory_bodies/impact_measurement_t askforce/en/index. html