Epidemiology of complex regional pain syndrome in Korea: An electronic population health data study

Chronic regional pain syndrome (CRPS) is an inflammatory and neuropathic pain disorder characterized by the involvement of the autonomic nervous system with sensory, autonomic, motor, skin, and bone changes. At present, universally accepted consensus criteria for CRPS are not yet established, despite the diagnostic criteria proposed by the International Association for the Study of Pain (IASP). Various hypotheses for the pathophysiology of CRPS have been proposed; as a result, current therapeutic modalities are varied. General epidemiological data on CRPS are necessary for effective management. However, recent data on the epidemiology of CRPS in Korea are scarce. The aim of this study was to evaluate the incidence and other epidemiological features of CRPS in the general population in Korea. In this study on the epidemiology of CRPS in Korea, population-based medical data acquired from 51,448,491 subscribers to the National Health Insurance Service (NHIS) from 2011 to 2015 were analyzed, including the incidence, distribution by the CRPS type, regional distribution, monthly distribution, medical costs, and healthcare resource-utilization. The findings indicated that the incidence of CRPS in Korea was 29.0 per 100,000 person-years in 2015 and was correlated with patient age and sex. CRPS types included type I (63%) and type II (37%); moreover, the number of individuals with CRPS I have shown a growing trend since 2011. There was no monthly distribution, but there was regional variation according to the province. The medical departments managing CRPS I the most were orthopedics, internal medicine, anesthesiology and pain medicine, in order; however, patients with CRPS spent more money per visit in the departments of rehabilitation medicine, and anesthesiology and pain medicine. The incidence rate of CRPS in Korea was 29.0 per 100,000 person-years with an increasing trend, which was correlated with patient age in the 70s and female sex. CRPS type I was more common than CRPS type II; in addition, constant increase in medical expenses, regional imbalance, and differences in medical expense among medical specialties should be considered for early management of patients to reduce the disease burden in Korea. Sharing of knowledge about the diagnostic criteria of CRPS are also needed.