An integrative review of implementation science in climate change and health adaptation research^,

Highlights

• •The formal use of implementation science in published CCHA research is limited.
• •Opportunities exist to adapt implementation science frameworks to CCHA research.
• •Investing in these opportunities can improve uptake of CCHA interventions.

Abstract

Introduction

As climate change accelerates, reducing associated health risks requires uptake of effective approaches to adaptation at scale. However, translating climate change and health adaptation (CCHA) interventions into practice remains a persistent challenge for both researchers and practitioners. Implementation science provides tools to study methods and strategies that facilitate the adoption and sustainability of interventions into practice, but its application in the CCHA domain has not yet been examined.

Methods

In response, this integrative literature review identifies how implementation science has been applied to assess determinants, strategies, and outcomes of CCHA interventions, and to evaluate gaps, strengths, and limitations in the existing literature. Nineteen articles were identified through systematic searches of four databases and expert recommendations. Discrete data domains, defined a priori, were extracted and synthesized across articles.

Results

Findings demonstrated wide variability in the use of implementation frameworks, the identification and assessment of implementation strategies and outcomes, and the overall conceptualization of CCHA interventions. Findings highlight a critical opportunity to leverage implementation science as a tool to strengthen the assessment and uptake of CCHA efforts in public health practice.

Conclusion

In the face of the accelerating climate crisis, there is an urgent need for implementation science and climate change and health experts to work together to overcome conceptual and operational challenges to the use of implementation science frameworks and methods to advance the field.

Graphical abstract

1. Introduction

Climate change is now globally recognized to have catastrophic impacts on human health worldwide, particularly in low- and middle-income countries and for historically marginalized populations [1,2]. There have been significant efforts to study the mechanisms and pathways between climate-sensitive exposures and health, including both the physical (e.g., respiratory [3,4]) and mental and behavioral health impacts [5,6]. Indirect health impacts of climate change have also been identified, including the disruption of medical services due to hospital power supply interruptions during extreme weather events [7], climate-induced malnutrition from impacted crops [8,9], and heightened mortality and injuries from conflict over environmental resources [10].

Concurrently, adaptation interventions that alleviate the health impacts of climate change are gaining traction. As defined by Huang et al., public health adaptation to climate change includes both short- and long-term interventions that “can reduce adverse health impacts or enhance resilience in response to observed or expected changes in climate and associated extremes" [11]. For instance, wildfire early warning systems prevent significant mortality by allowing for early evacuation [12]. However, as with any public health intervention, numerous factors, dependent on setting and population, influence adoption. This was evident in the 2017 Australia bushfires, during which individuals exhibited mixed responses to evacuation orders, resulting in a delayed evacuation process and low adherence to the warning system [13]. Importantly, there are significant inequities in the distribution and reach of early warning systems for climate-sensitive hazards [14].

Climate adaptation frameworks, such as the original Building Resilience Against Climate Effects (BRACE) framework [15] and its recent update [16], are valuable tools for distilling climate change and health adaptation (CCHA) interventions into a step-by-step process and can aid public health agencies in identifying holistic approaches to incorporating CCHA into programs as well as adaptation assessments and adaptation plans [2]. Moving from risk assessment to identifying effective interventions and developing strategies for their implementation is an important challenge in building climate-resilient health systems [17]. As climate change progresses, it is crucial to understand how CCHA interventions can be implemented successfully to achieve maximum impact in protecting population health.

1.1. Implementation science and CCHA

The field of implementation science is focused on translating knowledge to practice, thus promoting the integration of evidence-based interventions into routine public health and health care settings to improve population health impacts [18,19]. When investigating the uptake of an intervention, implementation is often measured in three distinct categories: determinants, strategies, and outcomes, further described in Table 1.

Table 1.

Definitions and framework examples of implementation determinants, strategies, and outcomes.

Implementation Category	Definition	Framework Example	Examples
Determinants	Factors that influence implementation outcomes, often grouped into barriers, facilitators, and opportunities [24]	Consolidated Framework for Implementation Research (CFIR) addresses barriers and facilitators; organized into five domains [25]	• Innovation: The innovation/intervention that is being implemented • Inner Setting: Where the innovation is implemented (e.g., hospital, school) • Outer Setting: The context surrounding the Inner Setting (e.g., hospital system, school district) • Individuals: The roles and characteristics of people involved in implementation • Implementation Process: The activities and strategies used to put the innovation into practice [25]
Strategies	Methods or techniques used to enhance the implementation of an intervention [26]. Defining strategies has been complicated by inconsistent terms and definitions, as well as insufficient guidance that enables replication of strategies in practice [27]	Expert Recommendations for Implementing Change (ERIC) provides common definitions and categories for implementation strategies to guide research and practice [[26], [27], [28]].	Conducting local needs assessments, developing education materials and resource sharing agreements, tailoring implementation strategies to better address determinants [26]
Implementation Outcomes	Indicators of the success of implementation processes that assess improvements at the population level. Distinct from service system and clinical treatment outcomes– serve as key intermediate outcomes before clinical or service outcomes [29]	Proctor’s Implementation Outcomes Framework [29]	Acceptability, adoption, appropriateness, feasibility, fidelity, implementation cost, penetration, sustainability [29]

The timeline for translating research to practice is particularly lengthy for environmental health interventions, even longer than the standard estimate of the 17-year research-to-practice gap for clinical interventions [20]. For example, toxic air pollution has long been identified as hazardous to human health, but policy action to reduce exposures remains insufficient [21]. Specific to CCHA research, case studies have identified numerous implementation barriers, including a lack of financial investment, limited coordination and climate knowledge among the health sector, and limited availability of climate data [22,23]. Given these identified challenges and the increasing rapidity of climatic change, there is an enormous opportunity to leverage implementation science to better understand how to successfully implement CCHA interventions and protect human health by increasing the rate at which effective interventions are implemented. However, a gap remains in understanding how implementation science has been utilized thus far to investigate CCHA interventions.

This integrative literature review aims to identify existing examples of the use of implementation science to assess implementation determinants, strategies, or outcomes of CCHA interventions and to assess the strengths and limitations of these articles. The findings of this review will provide insight into the current state of implementation science methods in CCHA research, identifying current trends, gaps, and best practices. This review can guide researchers in applying implementation science to CCHA interventions, ultimately informing best practices for improving research-to-practice translation time on the urgent health threats of climate change.

2. Materials and methods

We conducted an integrative literature review [30] to identify existing examples of the use of implementation science to assess implementation determinants, strategies, or outcomes of climate change and health adaptation interventions and to assess the strengths and limitations of these articles. An integrative review summarizes and analyzes both experimental and non-experimental research to provide a broad understanding of the research topic [30]. We chose an integrative review because we expected limited literature for the topic and intended to include multiple article types. Integrative reviews have been applied in similar studies seeking to identify the application of implementation science methods in health interventions, such as in adolescent healthcare research [31].

We implemented our search in four databases. Based on a previous review of implementation science journals [32], we also manually searched three specific journals: Implementation Science; BMC Health Services Research; and Implementation Research and Practice. Search terms included keywords related to implementation science, climate-sensitive hazards and exposures, and public health, and are described in further detail in the Supplementary Material. Specific climate-sensitive hazards and exposures were identified from Section One of the 2024 Lancet Countdown, “Health Hazards, Exposures, and Impacts” [2], including heatwaves, wildfires, extreme heat, drought, extreme precipitation, sand and dust storms, smoke, air pollution, dengue, malaria, vibrio, West Nile virus, flood, waterborne disease, foodborne disease, and airborne disease. A librarian at the University of Washington Health Sciences Library was consulted for defining the search strategy.

We limited our search to results between 2006 and 2025, as the implementation science field was formalized through the creation of the “Journal of Implementation Science” in 2006 [33]. Other inclusion criteria were that all articles be peer-reviewed (i.e., no dissertations or theses), original research (i.e., no literature reviews), examine adaptation to a health hazard or exposure related to climate change (as defined by the 2024 Lancet Countdown [2]), and examine the implementation determinants, strategies, and/or outcomes of a CCHA intervention. Following preliminary review of article titles, the research team made the decision to exclude articles focused on infectious disease and clean cooking stoves because these articles lacked clarity on adaptation to the health impacts of climate change as an explicit motivation for the interventions. For instance, articles on clean cooking stoves largely focused on health interventions to protect individuals from indoor air pollution generated by solid fuel-powered cooking stoves. In addition, we excluded case studies, opinion pieces, articles assessing the prevalence of a disease without examining a health intervention, or articles focused on COVID-19, flu, or exposure to cigarette smoke. A recent literature review identified implementation costs as the least studied implementation outcome, possibly due to the fact that cost can only be assessed during later stages of the implementation cycle [34]. Given that the field is relatively new, we did not expect that many CCHA interventions would have reached this stage of implementation, and we chose to exclude implementation costs. Articles were limited to the English language.

Two researchers (AK and CM) performed literature searches in February of 2025 and again in July 2025. After online searches were complete, three experts on CCHA and implementation science (including co-author NAE) were consulted by email to identify additional articles that may have been missed. Articles were screened in three phases by both researchers: title; abstract; and full text. At each phase, discrepancies were adjudicated (by AK and CM), and a third researcher (SW) made a final determination on any unresolved discrepancies. All authors reviewed the abstracts and agreed on the final selection of papers for inclusion. Fig. 1 provides a PRISMA flow diagram of the literature screening and identification process [35].

Fig. 1.

PRISMA flow diagram of literature search and selection process.

Following full-text review, discrete domains of data identified a priori were systematically abstracted and manually summarized from each article independently by two researchers (AK and CM) in Google Sheets. These domains included component(s) of implementation assessed, examples of each implementation component, framework(s) used, and key strengths, limitations, and takeaways. Results from each researcher were then synthesized by one researcher (AK) and manually entered into an overall matrix in Google Sheets. There were minimal differences between researchers, which were adjudicated through discussion by AK and CM.

3. Results

A total of 19 articles, provided in Table 2, met our inclusion criteria. Eighteen of the final articles addressed climate change directly; one article focused on intensive care unit (ICU) evacuation preparedness related to hospital fires [[36], [37], [38]]. The geographic distribution of study locations by continent is shown in Fig. 2, with roughly half (n = 9) of the final articles conducted in locations within the United States (US). As demonstrated in Fig. 3, interventions addressed three thematic study context areas, reflecting the primary organizational setting in which each study was conducted. These study context areas were identified through mutual consensus between authors. As an example, public sector CCHA interventions (n = 11) spanned various governmental levels. For instance, one article focused on the integration of health equity into federal health and climate change policies in Nepal [39], while another studied general climate preparedness among local public health departments in the US [40]. The “Other” study context area included diverse contexts, including agroforestry and maternal health. Examples of interventions included community-based agroforestry techniques, cooling centers for extreme heat events, and hospital evacuation procedures in response to flooding.

Table 2.

Final articles included in integrative literature review and study context area.

Article Title	Author(s)	Year Published	Source	Study Context
Assessing adaptation strategies for extreme heat: a public health evaluation of cooling centers in Maricopa County, Arizona [41]	Berisha, V., Hondula, D., Roach, M., White, J.R., McKinney, B., Bentz, D., Mohamed, A., Uebelherr, J., & Goodin, K.	2017	Cited/cited by article	Public sector
Exploring the scalability and sustainability of community-based agroforestry to achieve planetary health benefits in Haiti’s Lower Artibonite Valley [42]	Blaise, G.C., Allred, S.B., Morreale, S.J., Meredith, G.R., Sprenkle-Hyppolite, S., Buck, L.E., Jagadish, A., & Constas, M.A.	2024	Database search	Other
Climate Change Adaptation Activities and Needs in US State and Territorial Health Agencies [43]	Errett, N.A., Dolan, K., Hartwell, C., Vickery, J., & Hess, J.	2023	Expert recommendation	Public sector
Barriers and facilitators to state public health agency climate and health action: a qualitative assessment [44]	Hartwell, C., Lovell, S., Hess, J.J., Dolan, K., Vickery, J., & Errett, N.A.	2023	Database search	Public sector
Exploring barriers and facilitators to integrating health equity into health and climate change policies in Nepal – a qualitative study among federal level stakeholders [39]	Khanal, S., Baral, S.C. & Boeckmann, M.	2025	Cited/cited by article	Public sector
Lessons learnt from the 2021 Pacific Northwest heat dome: a qualitative study of western Washington's healthcare community response [45]	Korfmacher, M., Hartwell, C., Hill, K., Matthews-Trigg, N., Hess, J., Nori-Sarma, A., Wellenius, G., & Errett, N.	2025	Re-run database search	Healthcare system
Evacuation preparedness in the event of fire in Intensive Care Units in Sweden: more is needed [38]	Löfqvist, E., Oskarsson, Å., Brändström, H., Vuorio, A., & Haney, M.	2017	Cited/cited by article	Healthcare system
Reducing Extreme Heat Impacts on Health in Pregnant Women and Infants: a community-based intervention in Kilifi, Kenya [46]	Lusambili, A., Scorgie, F., Oguna, M., Chersich, M., Luchters, S., Gon, G., Filippi, V., Kovats, S., McCawley, K., Hess, J., & Nakstad, B.	2025	Re-run database search	Other
Examining barriers and opportunities for sustainable adaptation to climate change in interior Alaska [47]	McNeeley, S.M.	2011	Cited/cited by article	Public sector
Strategic analysis of Iran’s climate resilient health system [48]	Mosadeghrad, A.M., Afshari, M., Dehnavi, H., Keliddar, I., Zahmatkesh, M., Isfahani, P., Sharifi, T., Shahsavani, A., Ostadtaghizadeh, A., Abbasabadi-Arab, M., & Yunesian, M.	2024	Database search	Healthcare system
Relocation Preparedness Measures Highlighted by an Australian Flood-affected Hospital’s Evacuation [49]	Naru, F.S., Churruca, K., Long, J.C., Sarkies, M., & Braithwaite, J.	2025	Re-run database search	Healthcare system
Adaptation to climate change in the Ontario public health sector [50]	Paterson, J.A., Ford, J.D., Ford, L.B., Lesnikowski, A., Berry, P., Henderson, J., & Heymann, J.	2012	Expert recommendation	Public sector
Adapting to the changing climate: an assessment of local health department preparations for climate change-related health threats, 2008–2012 [40]	Roser-Renouf, C., Maibach, E.W., & Li, J.	2016	Cited/cited by article	Public sector
Institutional barriers to climate change and health adaptation in Burkina Faso [51]	Sorgho, R., Bhatt, M., Danquah I., & Sauerborn, R.	2022	Expert recommendation	Public sector
Implementation of medication for opioid use disorder treatment during a natural disaster: The PROUD-LA study [52]	Springgate, B., Matta, I., True, G., Doran, H., Torres, W.V., Stevens, E., Holland, E., Mott, K., Ardoin, T.R., Nixdorff, N, Haywood, C., Meyers, D., Johnson, A, Tatum, T., & Palinkas, L.A.	2024	Database search	Healthcare system
Climate change and human health—what influences the adoption of adaptation programming in the United States public health system? [53]	Syal, S.S., Wilson, R.S., Crawford, J.M., & Lutz, J.	2011	Cited/cited by article	Public sector
Reducing subsistence farmers’ vulnerability to climate change: evaluating the potential contributions of agroforestry in western Kenya [54]	Thorlakson, T., Neufeldt, H.	2012	Cited/cited by article	Other
Implementation of climate adaptation in the public health sector in Europe: qualitative thematic analysis [55]	Turner, G.A., de’Donato, F., Hoeben, A.D., Nordeng, Z., Coleman, S., Otto, I.M., Hajat, S., & Kovats, S.	2024	Expert recommendation	Public sector
Strategies to reduce the harmful effects of extreme heat events: a four-city study [56]	White-Newsome, J.L., McCormick, S., Sampson, N., Buxton, M.A., O'Neill, M.S., Gronlund, C.J., Catalano, L., Conlon, K.C., & Parker, E.A.	2014	Cited/cited by article	Public sector

Fig. 2.

Geographical distribution of final article study locations by continent. Studies were conducted in North America (n = 11, 57.9 %), Africa (n = 3, 15.8 %), Europe (n = 2, 10.5 %), Asia (n = 2, 10.5 %), and Oceania (n = 1, 5.3 %).

Fig. 3.

Sankey diagram visualizing study methods, framework used, and implementation component assessed by study context.

Most articles used qualitative methods (n = 11). Interviews were the most common approach (n = 8), often in combination with other qualitative methods (n = 3), such as focus groups, document analysis, and field observations. Studies most often interviewed only intervention providers (n = 6), as opposed to interviewing both providers and users (n = 1), or only users (n = 1). All articles using only quantitative methods (n = 4) surveyed intervention providers. Mixed method approaches often combined either interviews, focus groups, or field observations with surveys or social network analysis. Two mixed-method articles utilized surveys with both quantitative and qualitative components, including open-ended questions that were thematically coded.

Only three articles used an implementation science framework (see Fig. 3), specifically the Consolidated Framework for Implementation Research (CFIR) [25], which was applied inconsistently. Two articles used CFIR to both inform focus group guide development and data analysis, but one aligned its findings with four CFIR constructs (40), while the other only selected CFIR components relevant to the study to include in data analysis (42). The third article that used CFIR only used it to categorize results (50). Other non-implementation science frameworks used across articles included the Strengths, Weaknesses, Opportunities, and Threats (SWOT) tool, Command and Control Safety Communication Assessment Triage Treatment Transport (CSCATTT), Moser and Ekstrom’s framework on adaptation barriers [57], a combination of typologies from various papers [[58], [59], [60]], the Center for Disease Control and Prevention Framework for Program Evaluation [61], Vulnerability and Adaptive Capacity Assessment [62], Health Equity Policy Process Analysis Framework [63], Schlosberg’s framework of environmental justice [64], and Turner et al.’s vulnerability framework [65].

The final articles addressed a combination of implementation science components (see Fig. 3). Examples of implementation science components, including determinants, strategies, and outcomes, are provided in Table 3. Notably, determinants were assessed in every article collected (n = 19), while strategies (n = 5) and outcomes (n = 5) were less frequently examined. Among determinants, articles assessed barriers more frequently (n = 19) than facilitators (n = 10).

Table 3.

Examples of implementation science components (determinants, outcomes, strategies) identified among final articles.

Component	Component Sub-Category	Examples
Determinantsa	Innovation Domain	• Degree to which CCHA interventions (e.g., extreme heat response strategies, medication for opioid use disorder (MOUD) protocols) can be tailored to fit the local context [52,56]
	Outer Setting Domain	• Lack of political will/polarization on climate change [40,44,51] • Strong social networks of intervention recipients supporting uptake [42,46]
	Inner Setting Domain	• Organizational leadership supporting CCHA action [39,43,44,50]
	Individuals Domain	• Insufficient knowledge/expertise of intervention providers on CCHA issues [39,40,47,50]
	Implementation Process Domain	• Cross-sector collaboration applied as a strategy to implement CCHA interventions [43,45,52]
Strategiesb	Develop a formal implementation blueprint	• Develop disaster preparedness plans, including procedures for communication between patients and providers and amongst providers, measures to support patient access to medication and quality providers, etc. [52]
	Promote network weaving and Build a coalition	• Scale agroforestry through institutional and social networks [42] • Establish partnerships to implement heat-health interventions [56] • Leverage collaborative networks with other organizations, providers, and community health workers to address the health needs of MOUD patients during disasters [52]
	Involve patients/ consumers and family members	• Involve family members in helping adjust chore schedules to protect women from heat [46]
	Develop educational materials and Conduct educational outreach visits	• Run educational/informational campaigns on extreme heat and public health [56] • Conduct behavioral heat-health intervention with educational materials about the health impacts of heat for pregnant women; materials delivered by community health volunteers through home visits [46]
	Conduct local needs assessment	• Conduct assessments to assess neighborhoods’ risk and response needs related to extreme heat [56]
	Facilitate relay of clinical data to providers	• Transfer patients with their clinical records during hospital evacuations for flooding to ensure continuity of care [49] • Ensure MOUD providers have access to patient electronic health records and contact information during disaster events [52] • Create lists of people who will have to shelter in place during extreme heat events [56]
	Change service sites	• Enforce telehealth for routine visits to MOUD providers [52]
	Strategies not aligned with ERIC	• Implement extreme heat preparedness and response strategies, including operating syndromic surveillance systems, distributing fans, opening cooling centers, installing green roofs, establishing extreme heat early warning systems [56] • Improvise an incident command system during hospital evacuations for flooding [49] • Use telecommunications technology for MOUD patients to keep in touch with providers, including social media, online patient portals, and health applications [52] • Implement policies facilitating access to MOUD, such as allowing opioid treatment programs to dispense more doses of methadone [52]
Outcomesc	Acceptability	• Acceptability of agroforestry to farmers as a strategy to reduce climate change vulnerability [54] • Acceptability of cooling centers to visitors, including seeking refuge from the heat and using the facilities’ other provided services [41]
	Adoption	• Adoption of ICU fire evacuation preparedness measures (e.g., presence of a disaster plan, annual fire evacuation training) [38] • Adoption of extreme heat and health interventions by government and nongovernmental organizations in four American cities [56]
	Appropriateness	• Appropriateness of agroforestry as a solution for farmers, given the impact of climate change on farmers’ productivity, their coping strategies for climate-related hazards, and their interest in well-being improvements [54]
	Feasibility	• Feasibility of community approaches to support the health of pregnant and postpartum women during extreme heat [46] • Feasibility of implementing heat interventions in terms of cost and resources [56] • Feasibility of agroforestry as a climate adaptation strategy for farmers [54]
	Fidelity	• Fidelity of ICUs’ fire evacuation preparedness processes as outlined (i.e., most ICUs had a written plan and an intention to perform regular evacuation training, but few consistently performed the training) [38]
	Penetration	• Reach of cooling centers to vulnerable populations [41]
	Sustainability	• N/A

^aExamples are categorized by implementation determinant domains from the 2024 CFIR [25].

^bExamples are compared to ERIC strategies defined by Powell et al. 2015 [26].

^cExamples are categorized by implementation outcomes outlined in Proctor et al. 2011 [29].

4. Discussion

This integrative review synthesizes the existing examples of the use of implementation science to assess implementation determinants, strategies, or outcomes of CCHA interventions, highlighting current trends, remaining gaps, and emerging best practices. Consistent with findings from implementation science reviews in other disciplines, the articles included in our analysis (n = 19) demonstrated wide variability in the use of implementation frameworks, the identification and assessment of implementation strategies and outcomes, and the overall conceptualization of CCHA interventions [66,67]. Qualitative research was most commonly employed, which is especially valuable in implementation science because it reveals how and why efforts to implement best practices succeed or fail, while also providing insight into decision-making processes by both providers and users [68]. Articles using mixed methods often evaluated multiple implementation components, highlighting an opportunity for future CCHA research to make greater use of mixed method designs. Similar to findings from a recent scoping review on the use of implementation science in healthcare system preparedness, the articles identified in our review were mostly conducted within North American locations, suggesting a consistent gap in applying implementation science methods to CCHA in other regions, specifically low- and middle-income countries [69].

Our review found a limited and inconsistent application of formal implementation science frameworks. Only three articles explicitly employed a framework, all of which applied the CFIR. This aligns with the recent aforementioned review examining implementation science in healthcare system preparedness, which found that CFIR was the dominant framework used amongst implementation science studies. The authors also found that determinant frameworks (i.e., CFIR) were used most often among their final articles, as opposed to strategy or outcome frameworks [69], similar to our own findings that implementation determinants were most often assessed. However, use of the CFIR was inconsistent in our study, as some papers drew on selected constructs for data collection or analysis, while others did not explicitly map findings onto its domains. This partial application underscores a broader gap in the adoption of implementation science frameworks within CCHA research. Most articles relied instead on loosely defined notions of “implementation,” often using the term without grounding it in a structured framework. Without consistent use of established frameworks, it remains difficult to compare findings across articles, identify mechanisms driving successful adaptation, or build a cumulative evidence base.

Articles exploring implementation strategies defined these inconsistently and did not clearly align definitions with established frameworks. Although five articles in our review explicitly identified implementation strategies, these were often misaligned with the Expert Recommendations for Implementing Change (ERIC) framework [26], which is primarily designed for clinical contexts. This highlights a conceptual gap in how implementation strategies are currently defined and operationalized for application to CCHA. For example, White-Newsome and colleagues outlined a broad scope of strategies to address extreme heat, including communication, plans, early warning systems, public education, real-time data collection during heat events, and outreach to vulnerable populations [56]. While some of these activities can be loosely mapped to existing ERIC strategies, such as developing and distributing educational materials, the ERIC framework conceptualizes strategies predominantly in relation to patient-level outcomes. Given that implementation science originated within evidence-based clinical medicine [18], its current frameworks may not adequately capture the multisectoral, population-level, and often non-randomized nature of CCHA strategies.

Similarly, implementation outcomes were inconsistently defined and measured among the final articles included in our review. Notably, none of the articles explicitly referenced RE-AIM (reach, efficacy, adoption, implementation, and maintenance) or Proctor’s taxonomy of implementation outcomes [29], which are widely recognized as the gold standard outcome frameworks in implementation science. Outcome terminology varied, with “adoption” and “feasibility” being the most reported. For example, Lusambili and colleagues examined the development, implementation, and evaluation of a behavior-change intervention designed to mitigate the burden of extreme heat on maternal and newborn health, explicitly citing adoption and feasibility as markers of implementation success [46]. These findings resonate with patterns documented in a recent review by Proctor et al., which found that acceptability and feasibility remain the most frequently studied implementation outcomes across diverse fields, while others, such as fidelity, cost, and penetration, are far less often addressed [34]. A recent review of implementations science and healthcare system preparedness discussed how these less commonly assessed outcomes can be challenging to study as they often require more resources and time to evaluate [69]. Taken together, this suggests an opportunity for CCHA research to integrate established definitions of implementation outcomes and to provide a broader understanding of implementation outcomes by studying those that are evaluated infrequently.

Additionally, the conceptualization and reporting of CCHA interventions varied considerably, echoing findings from prior implementation science reviews in other domains, such as HIV care [70]. In the early stages of article screening, many articles we identified examined broad perceptions of climate preparedness or adaptation capacity rather than testing specific interventions. This may reflect the evolution of climate and health practice, which tends to focus initially on landscape analyses and vulnerability and adaptation assessments [71]. For example, Carr et al. employed a survey to assess perceptions of general CCHA strategies among New York state local health department officials, revealing substantial differences in views on the health impacts of climate change [72]. Simultaneously, some articles described loosely defined CCHA interventions but were not eligible for inclusion because they did not analyze implementation components. For instance, Martinez et al. examined characteristics of local heatstroke prevention plans across Japan but did not study plan uptake or integration into practice [73]. Among the final papers included in our review, the most common type of intervention examined was programmatic efforts at the jurisdictional level (n = 9), often emphasizing barriers to implementation. These patterns suggest that CCHA interventions remain conceptually variable and operationally underdeveloped, underscoring the need for greater definitional clarity and more attention to implementation. It also likely reflects challenges determining whether an intervention is a CCHA, given that climate change has the potential to impact a large range of disease pathways [74] and, by extension, a very large collection of interventions. Future research should prioritize developing standardized definitions and reporting frameworks for CCHA interventions (broadly defined) to build a coherent evidence base and allow for meaningful cross-study comparison. Establishing clearer criteria for what constitutes a CCHA intervention could also strengthen the translation of research into policy, ultimately enabling public health organizations and practitioners to more effectively select, adapt, and scale interventions for public health and report on their implementation.

Collectively, the limited use of implementation science frameworks, misalignment between identified strategies and outcomes with existing frameworks, and inconsistent definitions of interventions suggest that peer-reviewed literature in the field of implementation science has not yet been fully leveraged to support the systematic assessment and improvement of implementation of CCHA interventions. Given the urgency of the climate crisis, addressing this gap is crucial for advancing knowledge about how to effectively design, scale, and sustain CCHA interventions - including modification of existing interventions in response to climatic change - in diverse contexts.

There are opportunities for both implementation scientists and climate change and health researchers to work together to address this gap. Our findings reveal that current implementation science frameworks may not be conceptually aligned with the complexities, multi-sectoral nature, and innovation inherent in CCHA. Moving forward, adaptation of existing frameworks and the creation of new ones will be necessary to ensure that implementation strategies in the CCHA field can be systematically categorized, evaluated, and scaled. Achieving this goal requires intentional collaboration between climate change and health experts and implementation scientists to identify shared priorities, develop standardized definitions of implementation components, and adapt or create frameworks that reflect the unique features and challenges of CCHA interventions. Future research should encourage the systematic integration of implementation science frameworks, while also considering the adaptation of current frameworks to better capture dimensions of CCHA. Funders could encourage this through targeted calls as well as ongoing expectation of reporting on implementation outcomes. Finally, providing graduate education and training to emerging and tenured CCHA researchers, respectively, about the application of implementation science to their research can also facilitate the streamlining of implementation frameworks in the field. These efforts will support stronger comparability across articles and ultimately accelerate translation of CCHA interventions into practice.

4.1. Limitations

This integrative review has several limitations. Our search strategy, which used terms from Section One of the 2024 Lancet Countdown [2] and specific language on implementation science, may have missed relevant peer-reviewed literature, particularly articles that adhered to implementation science principles without specifically using implementation science terminology. To mitigate this potential issue, we asked three subject matter experts for recommendations and examined both the referenced lists of included papers and the “cited by” literature of each final paper. However, the exclusion of gray literature (e.g., reports, white papers, dissertations) remains a limitation, as these sources may contain evaluation of CCHA interventions not captured in peer-reviewed journals. For example, a 2018 dissertation by Zuber identifies barriers and facilitators to U.S. state and local health departments implementing the CDC’s BRACE model [75]. Future reviews should include gray literature to fully capture the global breadth of CCHA interventions. In addition, due to variability in the definitions and reporting of implementation components and interventions, some inconsistencies in categorization may have occurred during full-text review. We attempted to address this limitation by having two researchers independently conduct a full-text review and adjudicate discrepancies through consensus. Finally, this integrative review did not assess climate mitigation strategies, which future reviews can consider studying to capture a more holistic understanding of the application of implementation science in the climate and health field.

5. Conclusion

This integrative review highlights that the current application of implementation science within CCHA research remains limited and conceptually underdeveloped. Implementation science frameworks, the identification and assessment of implementation strategies and outcomes, and the overall conceptualization of CCHA interventions were inconsistent across the included articles, which impedes the development of a comparable evidence base to promote the uptake of interventions. These gaps underscore a pressing need to adapt existing implementation science tools, or develop new tools, that align with CCHA. Intentional collaboration between CCHA researchers and implementation scientists is required to accomplish the integration of implementation science and CCHA. Investing in the application of implementation science to CCHA is a necessary step to alleviate the intensifying adverse human health impacts of climate change and support the development of climate-resilient health systems.

Funding

This work was supported by the National Institutes of Environmental Health Sciences (NIEHS) [grant number P20ES036748].

CRediT authorship contribution statement

Amber S. Khan: Writing – review & editing, Supervision, Methodology, Formal analysis. Clare C. McCarthy: Writing – review & editing, Supervision, Methodology, Formal analysis. Stefan Wheat: Writing – review & editing, Supervision, Methodology, Formal analysis. Kenneth Sherr: Writing – review & editing, Supervision, Methodology, Funding acquisition, Conceptualization. Jeremy J. Hess: Writing – review & editing, Supervision, Methodology, Formal analysis. Nicole A. Errett: Writing – review & editing, Supervision, Methodology, Formal analysis.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.