Charting progress in learning health systems: A systematic review of 5 years of definitions, models, and frameworks

Abstract

Introduction: Since being introduced by the Institute of Medicine (IoM) in 2007, the learning health system (LHS) concept has gained traction as a promising solution for achieving systems-level healthcare transformation. This review of the LHS literature consolidates current understanding of LHS definitions, models, frameworks, and underlying theory, relative to their initial conceptualization by the IoM.

Methods: Three academic databases (PubMed, Embase, and Scopus) were searched for peer-reviewed literature between 2018 and 2023. Articles were included that explicitly focused on LHSs and described an LHS definition, model, or framework. Extracted article information included key article characteristics and article type; LHS definition(s) and their reference(s); components of LHS models or frameworks; and any reported theories underpinning LHS models or frameworks. Extracted data were examined using thematic and visual network analyses, and practical examples of how the domains of an LHS can be actualized in health settings were synthesized.

Results: The majority of the 226 included articles were nonempirical (47%) and originated from high-income countries (97%), with a significant portion from the United States (62%). A third of articles described an LHS implemented in a real-world setting (35%). A significant majority (82%) provided a definition of an LHS, with key concepts centering around "knowledge to practice," "workplace culture," and "informatics." Over half of included articles described an LHS model or framework. From thematic deductive-inductive coding of 145 LHS models and frameworks, most identified aspects related to Science and Informatics (83%) and a Continuous Learning Culture (81%), with the most prevalent sub-domain being Supportive System Competencies (76%). Implementation science was the most used theory to underpin existing models and frameworks.

Conclusions: By dissecting LHS definitions, models, and frameworks, we present an integrated framework that can serve as a useful tool for LHS researchers, clinicians, and policymakers working to improve health system performance and outcomes.

Keywords: definitions; frameworks; learning health systems; learning healthcare systems; systematic review; theory.

FIGURE 1

Increase in publications on learning health system over time, 2013–2023 (generated using data from PubMed on publications returned using the search term “learning health system” OR “learning health care system”). The raw count of search hits mentioning these terms is plotted by year. Dotted line: exponential trendline. LHS, learning health system.

FIGURE 2

Flow diagram for the study selection process.

FIGURE 3

Learning health system definition citation network. Each node in the network represents a definition reference, and the size of each node is indicative of frequency (i.e., larger nodes indicate a higher number of citations). The thickness of the lines (ties) represents the co‐occurrence of citations for a given definition reference. Different colors represent different clusters of citations.

FIGURE 4

Network analysis of key definition concepts. Each node in the network represents a key concept, and the size of each node is indicative of frequency (i.e., larger nodes indicate a higher number of times the concept was identified). The thickness of the lines (ties) represents the co‐occurrence of key concepts within a given definition. Different colors represent different clusters of definition concepts.

FIGURE 5

Network map of relationships between sub‐components of learning health system models and frameworks included in this review. Each node in the network represents a sub‐component, and the thickness of the lines between sub‐components represents the frequency with which they co‐occurred. Nodes are colored according to the six LHS domains described in this review, comprising the five domains of the modified IoM Model with the added domain of Equity and Ethics.

FIGURE 6

Conceptualization of the learning health system based on the findings of this review.