The diagnostic criteria for RAD in ICD-10 (WHO, 1992) are similar to DSM-IV, but the two subtypes from DSM-IV are classified as different diseases. HIRA system adopted Korean standard classification diseases (KCD) diagnostic codes, which is fundamentally based on ICD-10. HIRA claims data are a record of national insurance claims by a physician based on patient treatment records, and the diagnostic codes are determined by the clinician after treating the patient. According to the claims data from 2015, approximately 50,490,157 individuals (97.1%) had National Health Insurance (NHI), while 1,544,267 individuals (2.9%) had medical aid. The Korean National Health Insurance (NHI) claims database maintained by the Health Insurance Review and Assessment Service (HIRA) is a database containing all medical and prescription drug claim records for the Korean population. Beyond psychiatric comorbidities in patients with RAD the data for medical comorbidities lack. Physical problems such as delay in motor, weight and height sometimes occur.
![asd dsm 5 with comorbidities asd dsm 5 with comorbidities](https://image1.slideserve.com/2228878/comorbidity-l.jpg)
While RAD is persistent and associated with significant psychiatric morbidity, frequently with cognitive and language delays. Thus, evidence-based epidemiological studies of RAD have severe limitations. In a deprived population of children aged 6–8 years, the prevalence was 1.40% (95% CI 0.94–2.10%).
![asd dsm 5 with comorbidities asd dsm 5 with comorbidities](https://psychnews.psychiatryonline.org/cms/10.1176/appi.pn.2023.04.4.34/asset/images/medium/4-34-figure3.jpg)
Though Skovgaard estimated the prevalence to be 0.9% in 1.5-year-old children, RAD is usually not reported in community sample. RAD remains one of the least evidence-based area of DSM and International Statistical Classification of Diseases and Related Health Problems (ICD) nosology. RAD and DSED are very rare, with almost no empirical research published, and number of cases have been too few for analysis in DSM-5 field trials. Up to now, the published results of domestic prevalence on RAD were nonexistent, and international results are also very rare.