Objective  To analyze user log data of a national health risk factors monitoring information system for providing technical support to the optimization and data quality improvement of the system.

  Methods  Totally 522 638 user log records generated from 2018 through 2021 were derived from the health risk factors monitoring system – a subsystem of the China Information System for Disease Control and Prevention. The derived data were cleaned and analyzed to examine characteristics of user access and the operation/improvement of the information system.

  Results  The frequency of user access to the health risk factors monitoring information system was higher in the first half of the year than that in the second half of the year during the 4-year period. The users of the information system were mainly staff of centers for disease control and prevention (CDCs) at municipal-level (26.5% of total access) and district/county-level (48.6%). The frequencies of access to the information system differed significantly among the staff users of CDCs at various administrative levels in provinces in eastern, central and western China (χ² = 40.1, P < 0.001). Uploading and auditing data were predominant operations for the user access and the ratio of the two operations varied temporally in a year. Log analysis results revealed that user access to the information system for modification and deletion of population health-related data decreased obviously and the completeness of key variables increased yearly after the implementing optimization measures for the system.

  Conclusion  The analysis on user log records of an information system records can explore operation characteristics and user behavior of the information system for operative optimization and data quality improvement of the information system.