Effective Coverage in Health Systems: Evolution of a Concept.

Area of Science:

• Health services research
• Global health
• Health systems science

Background:

• Intervention coverage is a standard metric for health system performance.
• Effective coverage measures actual health gains, accounting for intervention decay.
• Understanding effective coverage is crucial for optimizing real-world health interventions.

Purpose of the Study:

• To review the origins, evolution, and application of effective coverage metrics.
• To identify areas for improvement in coherence, terminology, application, and visualization.
• To understand the influence of effective coverage approaches on policy and practice.

Main Methods:

• Narrative review of effective coverage metrics.
• Tracing the historical development and conceptual underpinnings.
• Analyzing applications across different diseases and income settings.

Main Results:

• The concept of effective coverage was proposed by the World Health Organization over 45 years ago.
• Its popularity grew with theoretical advancements and quantification tools.
• Applications span infectious diseases (HIV/AIDS, TB, malaria) and non-communicable diseases (diabetes, hypertension) in low- and middle-income countries.
• Significant variability exists in terminology and the inclusion of effectiveness decay steps.
• Health system factors cause substantial loss of service effectiveness, yet are rarely addressed in policy.

Conclusions:

• Effective coverage metrics have evolved significantly, with growing application.
• Inconsistent terminology and a failure to address underlying health system factors hinder policy impact.
• Future efforts should focus on standardizing metrics and integrating findings into health system strengthening strategies.