All Member States have been implementing the International Health Regulations (2005) (IHR) since they came into force, and an average of 70% have reported their implementation status to the World Health Assembly every year, with improvement since 2017. Until 2017, countries used IHR monitoring questionnaires to report their status; since 2018, they have used the revised State Party Annual Reporting (SPAR). This tool was revised according to the recommendations of the IHR review committee to simplify annual reporting and to add other monitoring and evaluation instruments. 4 The SPAR covers 13 core capacities for implementing the IHR, 24 indicators scored from 1 to 3 for each capacity and 5 capacity levels scored from 1 to 5 on an ordinal scale. The WHO IHR monitoring and evaluation framework has 4 components: annual reporting, voluntary external evaluation, after-action review and a simulation exercise to monitor and evaluate IHR capacity. Since use of these various instruments, we have observed changes in self-assessment and some reduction in self-reporting bias. The analysis reported here was conducted to validate the reduction in self-reporting bias and find possible explanations.