Survey on frequency of medical X-ray diagnosis in Jiangsu province

Objective: To survey the frequency of medical X-ray diagnosis and estimate the medical exposure levels of Jiangsu province in 2016, so as to be able to improve effectively the protection against medical radiation exposure. Methods: All medical institutions in the province were covered in the survey for their basic medical information by means of census method. Frequencies of diagnostic medical X-ray examination were studied using random sampling method in 31 medical institutions. A linear model was established by number of outpatients number of inpatients, number of staff and number of radiation workers to evaluate the medical examination frequency. Results: A total of 9248 pieces of medical X-ray diagnostic equipment by the end of 2016 in Jiangsu province, including 1110 CT scanners. The total frequencies of diagnostic medical X-ray examination were estimated to be 911.45 examinations per 1000 population, covering 239.25 per 1000 for CT scanning. The number of medical X-ray diagnostic equipment increased by a factor of 0.8 while CT scanners by a factor of 3.6 compared to 1999. Medical X-ray diagnostic frequency raised by a factor of 3.2 while CT frequency by a factor of 15.1 compared with previous data. Conclusions: The medical X-ray diagnostic frequencies in Jiangsu province was 1.9 times the value given in the UNSCEAR 2008 Report, close to those in some developed European countries. Compared with the study in 2015, the present study has made greater improvement in sampling technique for selection of hospitals and equipment, frequency estimation method and acquisition of influence factors. Estimates of medical X-ray diagnosis frequency are closer to actual level. Further improvement will be needed for the future survey, so as to further study medical exposure levels and to provide basic information for better patient protection. (authors)