Table 2.

Challenges for country-level TB modelling identified during guidance development process

1	Limitations in the data and evidence available to inform modelled analyses
2	Limitations in the ability of models to represent complex policy scenarios, such as targeting of risk groups not represented in existing models
3	Difficulty in anticipating factors that could negatively impact the outcomes of modelled policy scenarios, such as those that involve novel interventions or aggressive expansion of existing services
4	Difficulty in describing the uncertainty in modelled results and how this should impact decision-making
5	Differences in the modelling and estimation approaches taken by modelling teams, with the potential that different models could provide different policy advice, given the same country context and policy question
6	Scarcity of human resources (worldwide and within high-burden countries) to meet the demand for modelling technical assistance, and lack of information for country TB programmes on what modelling support is available
7	Differences in the level of experience, understanding or expectations of the modelling process by in-country stakeholders and international funders, and related to this, difference in the confidence placed in modelled analyses by local and international stakeholders