The main goal of this study is to evaluate the effectiveness of adaptive sequential implementation strategies based on facilitation in promoting the sustainable and widespread adoption and scaling up of the Integrated Care Pathway for Acute Asthma - ASMAbat across all Primary Care and Hospital Pediatric Services of Osakidetza - Basque Health Service.

Although evidence-based, multidisciplinary approaches have demonstrated efficacy in the management of pediatric asthma, substantial variability persists in the quality and outcomes of care for children experiencing acute asthma exacerbations. The Integrated Care Pathway for Acute Asthma - ASMAbat is a structured, evidence-informed framework designed to standardize care for patients presenting mild to moderate asthma attacks. It delineates the essential steps in clinical assessment, pharmacological management, and interprofessional coordination of care. Additionally, it incorporates quality indicators relative to diagnostic accuracy, assessment of disease severity, appropriateness of medication prescription, and the experiences of families and healthcare professionals. These indicators were refined through iterative consultations with key stakeholders (clinicians, families, and implementation partners) to ensure both clinical relevance and contextual feasibility.

The current study will be conducted across all Integrated Healthcare Organizations (IHOs) within the Osakidetza-Basque Health Service. This initiative builds on previous development and validation of the ASMAbat pathway in two IHOs, where implementation was evaluated using principles of implementation science. The expanded phase aims to systematically scale and adapt the pathway across diverse organizational settings within the Basque health system to enhance the quality, consistency, and sustainability of asthma care.

Three facilitation strategies have been developed to support implementation: (1) Internal Facilitation alone (Standard Scaling); (2) combined Internal and External Implementation Facilitation (IF); and (3) combined Internal and External Sustainability Facilitation (SF). Internal Facilitation is led by Clinical Leaders, professionals embedded within the health system who promote adoption and integration of evidence-based practices among their peers. External Facilitation is provided by experts with established experience in implementation science and quality improvement. External Implementation Facilitation focuses on supporting Clinical Leaders in diagnosing and addressing barriers to practice change using the Behavior Change Wheel framework, a theoretically grounded model for analyzing determinants of individual and collective behavioral change. In contrast, External Sustainability Facilitation emphasizes the identification and reinforcement of organizational, team-level, and individual factors necessary to achieve the long-term, system-wide institutionalization of the ASMAbat pathway into routine pediatric asthma management.

The overarching objective of this study is to evaluate the effect of scaling the implementation of the ASMAbat pathway across the Basque Health Service, with the overall goal of improving clinical management of acute asthma in children in accordance to recommended care and reducing variability across professionals and care settings. The primary scientific aim is to determine, among Pediatric Services demonstrating suboptimal response to the Standard Scaling (SS) strategy, the incremental effect of adding an Implementation Facilitation component on the appropriateness of the management of acute asthma episodes, which includes: a) the recording of the severity score, b) the assessment and recording of persistent asthma symptoms using the Pediatric Asthma Control Tool (M-PACT), c) the initiation or adjustment of maintenance treatment in cases of persistent asthma symptoms, and d) the administration of bronchodilator treatment via MDI with a spacer device. Secondary aims include evaluating, among services achieving adequate initial adoption through SS, the effect of introducing a Sustainability Facilitation strategy compared with maintaining SS alone during the subsequent phase, on the indicators of adequacy in the management of acute asthma episodes.

A Cluster-randomized Sequential Multiple Assignment Randomized Trial (SMART) design will be employed to test adaptive implementation strategies. All pediatric professionals belonging to 11 IHOs from Osakidetza-Basque Health Service and all acute asthma episodes in children aged 2-14 years during the study period will be included. During the first 8 months, all centers will receive the universal components of the ASMAbat Pathway and will be exposed to a standard scaling strategy (SS) composed of training for Clinical Leaders and pediatric professionals, electronic health record decision-support tools, audit and feedback, multichannel dissemination, and email reminders.

At month 8, based on the achieved implementation response (success criterion = Pulmonary Score recording rate exceeding 40% of all acute asthma episodes managed during the observation), external facilitation may be sequentially and randomly added as an adaptive strategy: for sites with poor adoption, facilitation will target barrier identification, problem-solving, and behavioural determinants; for sites with successful adoption, it will focus on sustainability by integrating the pathway into routine care. A second random reassignment will be conducted at month 16 based on response status, followed by an 8-month maintenance period, with a total follow-up of 32 months across all centers. Changes between periods by strategy in the rates of mild-to-moderate acute asthma episodes in which recommended treatment administration is recorded will be analysed using generalised linear mixed models. Implementation outcomes of reach and adoption of recommended care at patient and professional levels, fidelity of the clinical and implementation strategies, professionals' perceived feasibility, and user-reported care satisfaction will also be assessed.

This present study's design aims to maximize efficiency by first deploying the least complex, resource-intensive strategy and sequentially intensifying or modifying facilitation for sites demonstrating limited response, while maintaining existing strategies for successful sites. Such an adaptive approach minimizes costs by tailoring the level of implementation support to each site's readiness and observed progress. Furthermore, this design enhances the potential for scalability and generalizability across multiple contexts, including different clinical settings, patient subpopulations, and organizational environments. Ultimately, the project seeks to advance system-wide adoption and sustainability of evidence-based clinical practice for pediatric asthma management within Osakidetza, contributing to the broader field of implementation science and healthcare quality improvement.

Eligibility for healthcare settings:

- All Pediatric Services (Primary Care n=108 and Hospital Care n=9) from 11 of the 13 Osakidetza Integrated Healthcare Organizations that are not currently implementing the ASMAbat Pathway.

Eligibility for professionals:

• Primary Care pediatricians and nurses
• Pediatricians and nurses in the Pediatric Emergency Department
• Pediatricians and nurses on the inpatient ward
• Pediatric Intensive Care pediatricians and nurses
• Pediatric Pneumology pediatricians and nurses

Eligibility for patients:

Patients between 2 and 14 years that have being attended between the 1st of July 2026 and the 28th of February 2029, and with an acute episode of asthma, defined as:

• an episode of wheezing and a previous diagnosis of asthma or with a previous episode of wheezing
• a first episode in a child older than 2 years with a personal/family history of atopy and/or with an objective response to bronchodilators as assessed by a severity Score

Individual participant data will be shared that underlie results reported in the publication, after deidentification.

Starting 6 months after the publication of results.

Since data supporting the present study will mostly concern routine data retrieved from the electronic health record of the Basque Health Service-Osakidetza, it will be only shared on justified request to the study guarantors (proposals should be directed to the Responsible Party). It will only be shared with researchers whose proposed use of the data has been approved by an independent review committee identified for this purpose.