Importance: What occupational science (OS) knowledge may be essential to occupational therapy practice has not been systematically explored.
Objective: To identify and gain expert consensus on OS concepts viewed as essential to occupational therapy practice.
Design: A complex, convergent mixed-methods Delphi design with an international panel of OS experts randomly assigned to two parallel groups. In Round 1, each group generated OS concepts; in Rounds 2 and 3, they rated the degree to which each concept was essential to occupational therapy. Data were analyzed separately for each group. A fourth round combined the two groups and used carefully merged concept definitions from both groups to validate consensus on essential concepts arising from the prior rounds.
Participants: Fifty-two nominated experts from 22 countries who met a priori criteria participated in the 14-mo study.
Results: Of 62 experts invited, 52 (Group A = 24, Group B = 28) participated in the first round, and 42 (81%) completed the full-group final round. Eleven concepts met the consensus threshold (≥70%) established for the study. Additional analysis compared parallel- and full-group results to carefully discern conceptual similarities and differences, especially with near-consensus concepts.
Conclusions and Relevance: Substantial expert agreement was established for several OS concepts viewed as essential, providing a basis for future studies to refine the concepts for occupational therapy education and practice.
What This Article Adds: The results of this research provide a systematically derived preliminary basis for selecting OS content for occupational therapy educational programs and preliminary concepts for organizing OS knowledge germane to occupational therapy practice.