Constructing the cascade of HIV care: methods for measurement

Area of Science:

• Public Health
• Epidemiology
• Health Services Research

Background:

• The human immunodeficiency virus (HIV) treatment cascade is a widely accepted framework in global HIV policy.
• Estimating the cascade involves diverse methodologies, impacting long-term outcome assessment and sustainability.
• A standardized approach is crucial as the HIV response evolves.

Purpose of the Study:

• To review the history and current literature on HIV treatment cascade estimation methods.
• To develop a comprehensive typology classifying cascade scope and measurement dimensions.
• To provide recommendations for more robust cascade analyses.

Main Methods:

• Defining cascade scope by breadth (event range) and depth (number of stages).
• Distinguishing measurement based on data linkage (denominator-denominator, denominator-numerator).
• Analyzing data source populations (single vs. multiple) and study design (longitudinal vs. cross-sectional).

Main Results:

• Cascade scope can be defined by breadth and depth.
• Four key dimensions for cascade measurement were identified: linkage types, population scope, and design.
• Variations in methods significantly influence cascade estimation.

Conclusions:

• Broader and deeper cascades with denominator-denominator and denominator-numerator linkage are preferred.
• Longitudinal data from single populations are favored over cross-sectional or multiple populations.
• Investment in population-based cohorts and data linkage is essential for comprehensive longitudinal HIV cascade analyses.