Chronic diseases are on the rise in modern society as the aging population increases. The severity of underlying diseases and expectations that physical function and quality of life can be restored define the need for rehabilitation; thus, it is increasingly important to justify its medical effectiveness. For this purpose, outcome measures are widely used and can be based on different methodological approaches, such as questionnaires, performance tests, and functional physical examinations. Efforts to standardize these measures appear in the literature, but few publications have recently emerged on multiple medical outcomes, new promising approaches, or reference values in different rehabilitation phases or specific patient groups.

Several factors influence the course of convalescence during rehabilitation, leading to discrepancies in outcomes and a misleading pattern of bias. Therefore, influencing variables must be identified, such as age, sex, lifestyle, baseline values, time dynamics, environmental factors, and especially method choice and their scientific quality criteria.

This Special Issue provides an overview of recent advances in the field of outcomes research in rehabilitation, explaining how to use clinical data and findings from basic and applied research to actively shape the practice and future of rehabilitation as a basis for decision making on and management of medical interventions.

Potential topics include, but are not limited to, the following:

Rehabilitation (WHO Phases I–IV); Routine outcomes and applicability; Evaluation of treatment pathways; Effect sizes and reference values; Data collection requirements in routine and applied rehabilitation research; Methods and approaches in outcomes research; Cross-validation and performance of outcome measures; Moderating factors of outcome assessments; Critical success factors for successful rehabilitation; Translational research.