Practice Areas, Skills, and Core Competencies of Advanced Practice Physiotherapists Working in Tertiary Care in Germany: Protocol for a 3-Round Delphi Study to Establish Expert Consensus.

Background: Specifically in primary musculoskeletal care settings, the employment of advanced physiotherapy practice (APP) roles seems to be safe, as well as clinically and financially effective. In tertiary care settings, the implementation of APP roles is still in its infancy. A structured identification of relevant APP roles and a definition of practice areas, needed skills, and core competencies is widely pending. Objective: This study aims to identify and prioritize the most relevant areas of tertiary care for the implementation of APP roles within the German health care system. Additionally, it is aimed to achieve expert consensus on practice areas, needed skills, and core competencies relevant to execute identified roles. Methods: A total of 100 national experts will be invited to participate in a 3-round Delphi survey. Participants will purposively be sampled among physiotherapists with extensive clinical and/or academic experiences in German tertiary care. Data will be pseudonymized and collected via online questionnaires. In Delphi round 1, close-ended questions on relevant APP roles and open-ended input on practice areas, skills, and core competencies will be queried. Open-ended questions will be structured according to key domains of the National Health Service multiprofessional framework for advanced clinical practice. In round 2, participants will rate close-ended items on practice areas, skills, and core competencies that emerged from open-ended questions of round 1. Each item will be rated on a 7-point Likert scale ranging from "not relevant at all" to "extremely relevant." Consensus will be set on ≥70% agreement per item (including "5=fairly relevant," "6=very relevant," and "7=extremely relevant"). Items with agreements of ≤30% will be excluded. Items of 31% to 69% agreement will be reevaluated in round 3. Descriptive statistics (median, IQR, and absolute and relative frequencies) will be used to visualize response patterns, and McNemar and Wilcoxon signed-rank tests will be applied to explore changes between rounds. Results: Data collection took place between January and May 2026. For the first Delphi round, 98 experts were invited, of which 37 fully completed round 1. In round 2, these 37 experts were invited, of which 34 fully completed Delphi round 2. Following these response rates, we were confident to receive the targeted study sample of 20 experts after data collection of Delphi round 3 was completed. Data collection for the third and final round was completed in May 2026 and included 32 final respondents. Conclusions: Findings will support evidence-based APP role development and contribute to optimizing tertiary care areas relevant to physiotherapy care in Germany.