From accelerometer data to activity patterns in chronic pain: methodical reasoning is key

Activity pattern (AP) concepts are widely used in interdisciplinary chronic pain (CP) care. It is assumed that AP can be objectively measured with accelerometry, but previous results show inconsistencies which may be attributed to methodical choices. This scoping review aims to provide insight in the process of methodical reasoning for measuring AP concepts within CP and the implications for the validity of the methods presented. This process comprises (1) selection of the AP-related concept, (2) its definition or specification (conceptualization), (3) its operationalization with variables and indicators, and (4) measurement properties and data processing. Five databases were searched for full-text publications from inception to November 2024 and publications were included when AP were measured with tri-axial accelerometers for at least five consecutive days in adults with primary musculoskeletal CP. The searches yielded 11,648 papers. Fifteen papers were included and summarized in three tables: 1. Study characteristics, 2. Concepts, definitions and operationalization, 3. Measurement properties and data processing. Concepts were diverse and could be divided into behavioral concepts and concepts derived from physics. Methods were heterogeneous, reporting of methods was incomplete and validity was doubtful in multiple cases. This review provides recommendations for future research steps that could facilitate the comparison of upcoming studies and their application in daily practice. As a first step in securing comparability and usability of future research, consensus is needed on clinically relevant and valid AP concepts and their definitions, followed by consensus on operationalization, data processing, and measurement methods. Systematic Review Registration: 10.17605/OSF.IO/A8U6J.