Abstract: ObjectiveTo analyze the changing rule of the outpatient amount of hospitals from the regional health information platform (RHIP) of Guangdong Province, examine the correlation of the changing rule and time trend of outpatient amount between RHIP and the influenza like illness surveillance system (ILISS), and explore the feasibility of replacing the data from ILISS with data from RHIP.MethodsOutpatient clinical data were collected from 8 hospitals with high data quality in cities G and F during 2012 - 2014 through RHIP of Guangdong Province. Meanwhile outpatient clinical data were collected from 9 sentinel hospitals of influenza surveillance in the same cities and periods through ILISS of China Influenza Surveillance Information System. A correlation analysis between the two sets of data was conducted and seasonal index changes of outpatient visits in one year were analyzed by the time series analysis method.ResultsPercentages of monthly amount of outpatient visits in yearly amount of outpatient visits were similar between the two sets of data. The correlation analysis showed that the Pearson correlation coefficients were 0.646 for City G and 0.624 for City F (Both P<0.01). For City G, the analysis of seasonal index of outpatient amount showed that the seasonal indices were over 100.00% in March to August, and December for data of RHIP, and in March - July, September, and December for data of CNISIS for ILI, and the peak periods of outpatient visits appeared in March - July, and December for both systems. For City F, the seasonal indices were over 100.00% in March - August, and December for data of RHIP, and in March - June for ILISS, and the peak periods of outpatient amount appeared from March to June for both systems. The line chart showed that the seasonal index from RHIP had high similarity with that from ILISS.ConclusionThe monthly distribution of the outpatient amount from RHIP was basically consistent with that from the ILISS. Therefore, it may be feasible to use the outpatient data from RHIP to replace the data from ILISS.