The new chronic pain MG30 category and diagnostic specificity in quality registries—problems and suggested solutions with special reference to Swedish Quality Registry for Pain rehabilitation (SQRP) - Bäckryd, Emmanuel; Novo, Mehmed; Hallsén, Johanna; Schultze, Stefan; Rivano Fischer, Marcelo; Gerdle, Björn (Frontiers in Pain Research, 2024)