Objective To analyze the situation of duplicate reporting and changing trend of hepatitis B cases in Henan Province from 2016 to 2023 in the information system of the Chinese Center for Disease Control and Prevention, and to provide data references for improving the quality of hepatitis B reporting.

Methods Download the report cards from the information system of Chinese Center for Disease Control and Prevention, based on the name, date of birth and valid identification number, set the conditions for heavy trucks, and use Python to analyze the re-reporting situations within the year, across years, regions and reporting medical institutions.

Results A total of 571032 hepatitis B reporting cards were reported in Henan Province from 2016 to 2023. After data cleaning, 516313 cards were included, accounting for 90.42%. The composition ratio of duplicate cards over the past 8 years was 9.92% (511198/516313), mainly due to cross-year re-reporting, accounting for 91.53%. Among the confirmed cases, the proportion of duplicate cards within the year was 1.9%, which was higher than that of the clinically diagnosed cases (0.29%).The composition ratio of duplicate cards of chronic hepatitis B is higher than that of acute and unclassified cases. When it comes to cross-year rereporting, the more years span, the greater the duplicate cards ratio. The highest is an 8-year span, with a duplicate cards of 9.92% . The lowest is a 1-year span, with a duplicate cards ratio of 3.84%.When re-reporting across years, the maximum number of re-reports was 8 times, with the majority being re-reports 2 times, accounting for 89.40%.Duplicate report cards were reported in different regions of the province. The top three cities of duplicate report cards were Jiaozuo (10.49%), Puyang (9.97%), and Hebi (9.86%), and the overall cross-regional duplicate reporting composition ratio was 2.22%.The composition of duplicate cards by reporting units was 11.08%. Among them, 92.43% were chronic hepatitis B. In the same year, the reporting unit duplication was mainly cross-unit duplication, accounting for 72.99%.

Conclusion Chronic hepatitis B duplicate reporting primarily stems from recurrent case entries across different years and healthcare facilities, coupled with an under-optimized deduplication function in the digital reporting system. These factors contribute to the persistence of duplicate reporting. There is an urgent need to develop a practical and efficient deduplication mechanism to enhance data quality and minimize redundant reports..