Getting started: for everyone

A non-technical introduction to subnational tailoring (SNT) and how the SNT code library fits into the wider SNT process.

What are SNT and SNT analysis?

Subnational tailoring (SNT) is the tailoring of a country’s malaria response subnationally to account for and appropriately address local heterogeneities in malaria transmission, its determinants, and the likely impact of various intervention strategies.

Why subnational tailoring?

Malaria burden, transmission drivers, and intervention performance all vary widely within a single country. A single national strategy applied uniformly cannot fully account for this heterogeneity and may not make the best use of limited resources. With constrained funding and diminishing marginal gains from uniform coverage, programmes increasingly need to match the right interventions to the right places at the right time. SNT provides a structured way to do that, using available data and evidence to inform where, when, and how each intervention is delivered.

What questions does SNT help answer?

SNT analyses are most useful when they help the SNT team answer concrete operational questions, for example:

  • Where should ITN distributions be prioritised, and at what frequency?
  • Which districts should add seasonal malaria chemoprevention, and for which target age groups?
  • Where is case management most under-resourced relative to burden?
  • Which areas should receive intensified surveillance versus standard surveillance?
  • How should limited budget be allocated across interventions and geographies?

The exact questions vary by country and depend on the priorities set by the SNT team.

New to SNT acronyms? See the Acronyms reference for a single page covering every acronym used across the library.

How SNT fits into national planning

SNT is an evidence-informed, data-to-action process where many types and sources of data are considered together to inform the tailoring of the malaria response. The steps in the SNT process are intended to align with and provide additional evidence during standard malaria planning and implementation processes. WHO has issued guidance for countries on the preparation of national malaria strategic plans (NMSPs) and related programme reviews, operational plans, and costing, all aligned with national health sector plans. SNT should be nested within these processes and timelines: it is not a separate process, as it is aimed at directly informing the programme reviews, NMSPs, resource mobilization, and implementation.

The analysis steps of SNT include data assembly and management, situational analysis, stratification of malaria transmission and its determinants, review of past interventions, application of targeting criteria, mathematical modeling, and cost-effectiveness analysis. These analysis steps are interspersed with review, discussion, and validation by stakeholders under national malaria program (NMP) leadership to guide the analysis approach and make key decisions.

Full information on SNT is available in WHO’s Manual for subnational tailoring of malaria interventions, published in October 2025.

What to expect from the SNT process

A full SNT exercise typically spans several months from planning through validated outputs, with the exact timeline depending on country context, data availability, and how SNT is sequenced with the NMSP cycle.

While analysis is an important part of SNT, it is important to remember that the SNT process includes more than analysis. The WHO manual describes the full SNT process through 10 key steps (Figure 5 and Table 1):

  1. Planning and preparedness, including establishment of the SNT team
  2. Data assembly and management
  3. Situation reviews to understand the historical and recent epidemiological and intervention context
  4. Stratification of malaria epidemiology and its determinants
  5. Intervention tailoring
  6. Predicting the impact of intervention mix scenarios
  7. Developing costed strategic scenarios to generate a costed national strategic plan and preliminary prioritizations
  8. Optimizing strategic scenarios within available resources to generate costed operational plans
  9. Implementation and delivery of services
  10. Monitoring and evaluation of impact

The analysis team should work together with the rest of the SNT team to support all steps of the process, where the analysis may play a more or less prominent role.

Please see WHO’s SNT Manual for a full description of each step of SNT and AHADI’s SNT Roadmap Template for a comprehensive planning and timeline tool, resource list, and data checklist for the entire SNT process and related activities.

Roles

See Annex 1 — Terms of reference for the SNT team lead in WHO’s Manual for subnational tailoring of malaria interventions for the recommended composition and responsibilities of the SNT team and AHADI’s template terms of reference for the SNT team.

The SNT team is responsible for overseeing the entire SNT process, including analysis steps. It is led by the national malaria program and brings together the relevant national and subnational stakeholders, including implementation and technical partners.

The SNT team has a critical role in facilitating data access and assembly, giving direction to the analysis team, deciding on analytical approaches, validating (or not validating) results, and making decisions on which data is ultimately appropriate for which use, and how. Some SNT team members may also be part of the analysis team and directly participate in executing the analyses.

The analysis team is responsible for executing data management and analyses under the supervision of the SNT team. The analysis team has a responsibility to:

  • Generate analysis outputs (descriptive analytics, stratification maps, intervention mix maps, decision trees, scenario analyses, modeling results, and similar)
  • Explain the analytical approaches used along with their strengths and limitations
  • Present results clearly and transparently
  • Bring up considerations for the SNT team to address
  • Revise the approaches according to the direction and decisions of the SNT team

Who should use the SNT code library?

All are welcome to use and contribute to the SNT code library. We assume some basic knowledge of R or Python and some understanding of the types of data often used in SNT. The library is primarily aimed at analysts working under the direction of a national SNT team, but many elements may also be useful for general research and analysis work outside of a formal SNT process.

What does the SNT code library include?

The SNT code library includes code for many of the common data management and analysis steps of SNT, up to (but not including) mathematical modeling, along with some related analyses. Code included here stems from the experience of different analysts that have supported various countries and contexts through their SNT processes.

When multiple algorithmic options could be used, strengths and limitations of each one, along with discussion of when to use each option, are included as much as possible. We will still need to decide, in discussion with our supervising SNT team, what option to implement and will need to adapt the code to the specific database(s) we are working with.

Frequently asked questions

What’s the difference between this library and the WHO manual?

The WHO SNT Manual sets out what SNT is and how the SNT process should be run, including stakeholder engagement, prioritisation, and integration with national planning. The SNT code library is complementary: it provides quality-assured code for the analysis tasks that sit inside that process. The code library is designed to support the operationalization of the WHO SNT Manual.

Do I need to use all the code in the library?

No. The library is organised around common analysis steps for a typical SNT, and teams should focus only on the areas relevant to the indicators, data types, and analysis approaches of the SNT process with which they are engaged. Pick the pages that match our current question and adapt the code to our data.