[F45.41: chronic pain disorder with somatic and psychological factors : a coding aid]

In 2009, the German version of ICD-10 (ICD-10 GM version 2009) introduced the diagnosis of "chronic pain disorder with somatic and psychological factors", because current ICD-10 diagnoses did not address the biopsychosocial character of chronic pain adequately. For most patients, a dichotomous classification into psychologically versus biomedically caused pain is inappropriate and does not reflect current knowledge on pain. The new code F45.41 addresses the relevance of psychological factors for chronic pain persistence and chronic pain treatment, even in those conditions with a clear biomedical cause at the beginning. This guideline describes how to use this new diagnosis, which boundaries have to be considered, and how comorbid and associated conditions can be classified. The distinction of this new diagnosis from other pain-associated diagnoses and recommendations for the coding of comorbid conditions are presented. The differentiation of everyday pain symptoms from pain disorders is outlined. Finally, contextual factors of the classification process, as well as problems in integrating this new diagnosis into diagnosis-related group (DRG) systems of financial reimbursement are discussed.