Identifying ambulatory care sensitive conditions: a systematic review of studies defining sets of diseases with avoidable hospitalisations in European countries.

backgroundAmbulatory care sensitive conditions (ACSC) are health conditions that can be adequately managed in the outpatient setting. Timely treatment and interventions may avoid the need for hospitalisation and emergency department visits.

objectivesWe aimed to identify ACSC lists developed for European populations.

designSystematic review. We included primary studies that aimed to develop a list of ACSC for the general population or subpopulations within European countries. Studies reporting a formal methodology were eligible. Systematic or narrative reviews, and protocols were excluded. DATA SOURCES: PubMed, Web of Science and Scopus were searched on 21 October 2025. Data search was complemented with the search for 'ambulatory OR preventable' in the websites of the WHO Regional Office for Europe, OECD (Organisation for Economic Co-operation and Development) and NHSOF (British National Health Service Outcomes Framework). DATA EXTRACTION AND SYNTHESIS: Two reviewers independently collected data on type of population, geographical coverage, bibliographic support, use of qualitative or quantitative methods, ontology system, as well as the identified conditions per list. Data on methodological characteristics was qualitatively synthesised. Conditions identified as ACSC were aggregated under International Classification of Diseases 10th Revision (ICD-10). Each primary study with Delphi component was assessed using the Diamond

resultsA total of 12 articles were included. Six European countries have lists developed for general populations. A total of 263 unique ACSC have been defined (932 codes) for the general populations. For the paediatric age, 28 conditions (70 codes) were identified, while 37 diagnoses (58 codes) were listed for the nursing home population. Most commonly identified ACSCs were infection-related, chronic cardiovascular or respiratory diseases. Delphi methods were employed in eight studies, with a median of 3 (2-3.25) rounds with a median of 36.5 (32.8-42.5) panellists. Risk of bias assessment yielded a quality score of 2 (out of 4) for six studies and of 3 for the remaining two studies. Remaining studies were assessed with JBI yielding a median 6.5 (6.0-7.0) points (out of 10 possible points). The most used code system was ICD-10. Use of nationwide real-world databases was limited to six studies. No identified ACSC lists explicitly fulfilled all criteria defined by Solberg and Weissman for ACSC establishment.

conclusionsThe evidence on ambulatory care sensitive conditions is heterogeneous and derives from different methodologies and covers six European countries. Most lists are diagnosis-based, aim at national, general populations and include Delphi components to define ACSC. We speculate that the future inclusion of primary care data could enhance ACSC evidence. PROSPERO REGISTRATION NUMBER: CRD42022349270.