Falls prevention in Outdoor Public Spaces: An Interdisciplinary Delphi Consensus on Risks, Actions, and Barriers

Background Falls are the leading cause of accidental injury among older adults, with nearly half occurring outdoors. These falls are complex, understudied, and insufficiently addressed in current age-friendly cities or walkability frameworks. This study aimed to build interdisciplinary consensus on risks, preventive actions, and barriers to fall prevention in outdoor public spaces through a Delphi process. Methods A three-phase Delphi study was conducted with 64 participants in round 1, 60 in round 2, and 49 in round 3, including four expert groups: older adults who had fallen outdoors, health and research professionals, urban planners, and decision-makers. Phase one collected open responses on risks, preventive actions, and barriers. Responses were synthesized using AI-assisted analysis with systematic human validation. In phases two and three, the relevance of 124 propositions were rated on a 10-point Likert scale. Consensus was defined as ≥ 70% of ratings ≥ 7/10 and interquartile range ≤ 2.5. Results Consensus was reached for key intrinsic factors (e.g., gait and balance impairments, visual and vestibular deficits, cognitive decline, polypharmacy) and environmental factors (e.g., irregular or inappropriate surfaces, obstacles, signage not adapted, crowding). Highly relevant preventive actions included integrating fall prevention into street and sidewalk design, training urban planning professionals, awareness campaigns, systematic maintenance, safer crossings, participatory co-design, and improved data monitoring. Main barriers were insufficient budgets, high costs, limited integration of fall prevention into planning priorities, and lack of evaluation. Conclusions Outdoor fall prevention is a transversal challenge requiring integration of public health and urban planning. This Delphi highlights actionable priorities to embed fall prevention in local and national strategies, in particular in rapidly aging regions.