Study on estimation of medical exposure frequency in China

Objective: To study the estimation method of medical exposure frequency in China through the survey of diagnostic radiology and radiotherapy institutions in selected provinces. Methods: A survey of medical exposure frequency was carried out involving 557 diagnostic radiology and radiotherapy institutions in 25 provinces. The correlation analysis and multiple linear regression analysis were conducted, with the fitting effects of the models with different variables being compared. Results: The total medical exposure frequencies highly correlated with number of outpatient, number of equipment and number of radiation workers (| r | > 0.5). Representative samples of the daily medical exposure workload were obtained by stratified random sampling from the survey data. Mathematical models were built using the multiple linear regression between total medical exposure frequency and hospital levels, number of outpatients, number of inpatients, number of equipment, and number of radiation workers. The total medical exposure frequency in 2016 was estimated to be 589 million examinations based on the models. In addition, the frequencies of medical procedures were derived using the robust regression and the median regression. Conclusions: There are several methods for estimating the total medical exposure frequency. It is desirable to use the stratified random sampling combined with the published statistical and monitoring data. The representativeness of sample is critical. The specification and optimization of models also require further study. (authors)