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From Cases to Consumption

Evaluating CHAP/DHIS2 Model Portability for Health Supply Chains

Data Lab for Social Good, Cardiff University in collaboration with HISP Centre, University of Oslo

2025/10/29



Outline

Background

The fundamental question

What we are going to do

Our current plan

Initial results

What NEXT?

BACKGROUND

The Problem: A tale of two data streams


Health supply chains are struggling with forecasting at sub-national/ facility level.

  • Operational realities: Incomplete records, irregular orders, frequent manual adjustments.

  • This masks true demand and leads to a cycle of…

  • Persistent, critical stockouts 📉.


But… we have a success story.

Platforms like DHIS2 and CHAP have robust, high-performing models for forecasting disease cases (morbidity).

The fundemental question


✅ We’re good at forecasting cases (e.g., malaria).


❌ We’re struggling with forecasting consumption (e.g., antimalarials).



Can we leverage the CHAP/DHIS2 morbidity models to forecast product consumption in supply chains?

The challenge: Why isn’t this easy?


Case data and consumption data are different.


Different Data Structures

Consumption data is “messier”.

  • Missing entries (e.g., “0” = no consumption, or “0” = data not entered?)
  • Intermittency (infrequent demand).
  • Inconsistent recording.

Different Metadata

Consumption is affected by logistics.

  • Lead times.
  • Procurement cycles.
  • Existing stock levels and stockouts.

OUR APPROACH

Our research questions


To solve this, we are investigating three key questions:


Portability: When can we transfer a model? (Morbidity \(\rightarrow\) Consumption? One product \(\rightarrow\) Another?)


Decision Translation: How do we turn a statistical forecast into a better inventory order? (Forecast \(\rightarrow\) Action)


Hierarchical Coherence: Do site-level forecasts reliably add up for district and national planning?

What we are going to do


We’ve organized our work into three interconnected Work Packages (WPs).


WP1: Portability (Test reuse/transfer. Create “if/then” rules.)

\(\downarrow\)

WP2: Forecast \(\rightarrow\) Inventory (Translate forecasts into real-world inventory policy.)

\(\downarrow\)

WP3: Hierarchical Coherence (Test aggregation for national procurement.)

Our current plan

Our immediate focus is on WP1 (Portability) and linking to WP2 (Inventory Simulation).

INITIAL FINDINGS

Forecasting using morbidity data.

Data exploration

We used number of dengue cases in Laos to test the forecasting models.

Figure 1: Monthly dengue cases by location.

Ovreall forecast performance

Best values in each column are highlighted in bold.

Table 1
Model MASE Quantile Loss (q10) Quantile Loss (q50) Quantile Loss (q90)
Random Forest 0.864 107.360 383.058 607.857
ARIMA Madagaskar 0.902 165.565 360.123 310.765
Auto ARIMA Reg 0.913 173.929 367.735 322.289
Auto ARIMA 0.950 176.069 376.163 309.962
Linear Regression 1.008 129.647 416.129 278.839
LightGBM 1.009 96.771 452.020 752.016
Linear Regression Reg 1.035 127.927 391.573 284.118
Auto EWARS 1.041 125.371 421.408 296.665
xgBoost 1.057 103.980 485.837 817.878
INLA baseline 1.082 126.139 432.163 239.886
Mean 1.090 138.155 461.150 347.705
ETS 1.099 124.722 428.761 299.443
sNaive 1.217 138.155 510.311 276.443
Naïve 1.221 143.645 506.282 319.259

Ovreall point forecast performance across forecast origins

Figure 2: Overall MASE accross forecast origins

Ovreall point forecast performance across each location

Figure 3: Overall MASE accross forecast origins for each location.

WHAT NEXT

Way forward


Leverage CHAP/DHIS2 based models for supply chain data.


Evaluate forecast perfromance based on time series structure, region and across products.


Run order up-to-level based inventory simulations.


Evaluate how forecast performance translate into inventory decisions.

Key takeaways


The Idea: Reusing morbidity models for supply chains is a promising but non-trivial opportunity.


Our Contribution: We’re building an evidence-based, practical guide for when and how to repurpose morbidity models for consumption forecasting, leveraging CHAP’s modelling infrastructure and DHIS2-linked data.


The Impact: By aligning forecasts with operational decisions, this work aims to improve stock availability, and inform sourcing/procurement decisions.


Compatibility: CHAP/DHIS2’s external model interface makes it possible to integrate these forecasting tools seamlessly, no new platform required.

Any questions or thoughts? 💬