Comparison of Data and Performance Indicators: Before and After the Transition of Thailand’s National Disease Surveillance System, 2023–2024

In 2024, Thailand modernized its national disease surveillance system, transitioning from Report 506 (R506) to the Digital Disease Surveillance (DDS) system, replacing batch file reporting with an application programming interface (API). To compare the data characteristics and performance indicators between the DDS and R506 systems, a descriptive study was conducted using data from January to September 2023 for R506 and 2024 for DDS, obtained from the Department of Disease Control. The DDS system contained 1,567,885 records, while R506 had 980,934. The number of hospitals and health centers reporting to the DDS system was 3,402, while 5,319 reported to R506. Due to the ongoing transfer of health centers to the Ministry of Interior, fewer reports were sent from health centers to the DDS system (14,374) compared to R506 (44,298). Timeliness (median interval from diagnosis to report) was 1 days (interquartile range (IQR) 0–2 days) in R506 and 1 days (IQR 0–4 days) in DDS. The DDS system achieved 99.99% completeness for citizen identification numbers and 100% for diagnostic codes, while R506 achieved 49.75% and 41.59%, respectively. The DDS system had a larger contribution from Bangkok than R506 (25.45% vs 10.70%). In conclusion, the data characteristics of the DDS system remained similar to R506. However, the DDS system is less than one year old, and the ongoing transfer of health centers might affect the reporting coverage. Therefore, follow-up surveillance evaluation with an emphasis on qualitative attributes is recommended.