Interobserver agreement of medical research council sum-score and handgrip strength in the intensive care unit

Introduction: Muscle weakness often complicates critical illness and is associated with devastating short‐ and long‐term consequences. For interventional studies, reliable measurements of muscle force in the intensive care unit (ICU) are needed. Methods: To examine interobserver agreement, two observers independently measured Medical Research Council (MRC) sum‐score (n = 75) and handgrip strength (n = 46) in a cross‐sectional ICU sample. Results: The intraclass correlation coefficient (ICC) for MRC sum‐score was 0.95 (0.92–0.97). The kappa coefficient for identifying “significant weakness” (MRC sum‐score