Enhancing High‐Resolution Assessment in Pain Disorders: Development of an Adaptive Real‐Time Version of the Pain Catastrophizing Scale

BACKGROUND: Pain Catastrophizing Scale (PCS) scores have consistently been associated with heightened pain perception and poorer treatment outcomes. However, the PCS is typically administered as a trait-level measure and does not capture within-day fluctuations in pain-related cognitions. With increasing interest in real-time monitoring through Ecological Momentary Assessment (EMA), there is a need for reliable and efficient instruments suitable for repeated use without inducing response fatigue or bias. METHODS: The German version of the 13-item PCS was adapted using minimal linguistic modifications for momentary assessment. Based on a cross-sectional design, the original and EMA versions were administered to 691 and 1440 patients, who reported pain within the last week. Using Item Response Theory (IRT), we modeled item characteristics, confirmed unidimensionality, and developed three 4-item short forms to enable efficient and balanced assessment. In addition, we conducted computer-adaptive testing (CAT) simulations to examine expected measurement precision and item exposure effects under repeated adaptive use. RESULTS: The adapted PCS showed strong essential unidimensionality and high item discrimination. All short forms achieved high measurement precision across a broad range of symptom severity. CAT simulations confirmed high precision for initial assessments, though performance declined with repeated use due to the limited item pool. CONCLUSION: This study provides an initial psychometric evaluation of a momentary-adaptive PCS using IRT-based short forms and CAT simulations. Adaptive administration improved efficiency in early assessments but requires further validation in real-world EMA designs to establish longitudinal performance and applied utility. SIGNIFICANCE STATEMENT: This study introduces an adaptive, real-time version of the PCS optimized for ecological momentary assessment. By combining IRT-based short forms and computer-adaptive testing, the approach enhances measurement precision while reducing burden in repeated assessments. These findings represent a methodological step toward high-resolution monitoring of PCS-based pain-related cognitions in clinical and mobile health research.