The Diagonal Model was developed for addressing complex health system challenges. It helps reconcile and integrate previously perceived dichotomies between “vertical” disease-specific interventions and “horizontal” health system–strengthening initiatives. The approach aims to achieve specific health improvements while simultaneously building robust, resilient health systems.
The concept of diagonal approach was advanced by Frenk and colleagues in the 2000s based on the idea described by Sepulveda (2006). Historically, the global health field has been caught between two seemingly opposing strategies:
- Vertical programs focus intensely on specific diseases or health conditions, often with dedicated resources and delivery mechanisms that operate separately from the broader health system. While capable of achieving quick wins by tackling specific targets with a short-term focus, vertical programs can be criticized for creating sufficient investment in some areas but not others. They tend to neglect the wider determinants of health or the need for sustained system development.
- Horizontal approaches, conversely, aim to strengthen the health system as a whole, addressing system-wide constraints like workforce shortages or inadequate facilities. These interventions are focused on foundation building and are generally characterized as system-wide, multi-sectoral, and long-term. However, they have been criticized for being too broad, idealistic, and lacking clear priorities, potentially spreading scarce resources too thinly.
The Diagonal Model attempts to resolve this dilemma by advocating for an integrative strategy that combines the strengths of both. It can be thought of as a four-quadrant matrix, where one axis represents the ability to tackle specific targets and the other represents the “ability to build general capabilities. In the lower left quadrant are peripheral initiatives, which are low on both axes and yield little payoff. Quick Wins are high on specific targets but low on general capabilities, offering targeted, short-term success. Foundation building focuses on high general capabilities but low specific targets, concentrating on system-wide, long-term improvements. Transformation is more likely to occur when interventions are high on both tackling specific targets and building general capabilities.
For example, investments cold chain infrastructure (general capability) for vaccination programs (specific target) not only ensure vaccine efficacy but also benefit the overall operation of health units (spillover effects) by providing reliable electricity and refrigeration for other services. By considering the general capabilities necessary to tackle specific targets you may find a sweet spot or strategy that is effective for as many targets as possible.
Deeper Dive
- Frenk J. The Global Health System: Strengthening National Health Systems as the Next Step for Global Progress. PLoS Med 7(1): e1000089, 2010.
- Frenk J, O Gomez-Dantes, and FM Knaul. The Health Systems Agenda: Prospects for the Diagonal Approach. The Handbook of Global Health Policy, First Edition. Edited by GW Brown, G Yamey, and S Wamala, John Wiley & Sons, 2014.
- Sepúlveda J. Foreword. In: Jamison DT, Breman JG, Measham AR, et al., editors. Disease Control Priorities in Developing Countries. 2nd edition. Washington (DC): The International Bank for Reconstruction and Development / The World Bank; 2006.
Related Frameworks
- Complexity Theory of Outcome Creation: describes core capabilities needed to apply the Diagonal Model
- Six Conditions of Systems Change: describes domains that support implementation of a diagonal approach