Representativeness of D506 compared to the National Health Database (43-file) in Thailand during the early phase of D506 implementation

Introduction: Notifiable disease surveillance is a vital component of public health systems. Since the COVID-19 pandemic, public health agencies and healthcare professionals have been overwhelmed, and public health surveillance has been affected. The Division of Epidemiology digitalized the existing notifiable disease surveillance system (R506) by developing a D506 system piloting COVID-19 which has been fully implemented since January 1, 2023. We aim to describe the D506 system, evaluate its representativeness, and give recommendations for system improvements. Methods: We did a descriptive cross-sectional study by reviewing relevant documents of D506 to describe the system. Then we retrieved data of COVID-19 and pneumonia cases from D506 and the national health database (43-file). The study period was January 1–June 30, 2023. The study site was purposively selected to the hospitals from four regions of Thailand: North, South, Northeastern, and Central. We did a comparison between D506 and 43-file database for the representativeness. The D506 system received data directly from healthcare providers using an Application Programming Interface (API). Results: Overall, we discovered that the number of total COVID-19 and pneumonia cases differed markedly between the D506 and 43-file databases, especially for COVID-19 cases. When examining the sex distribution, COVID-19 cases showed a lower proportion of males compared to females in both the D506 and 43-file databases. In contrast, the male proportion was higher among pneumonia patients across both databases. When comparing age group distribution, address (province), and treatment date of COVID-19 cases, the D506 database underrepresented older age groups relative to the 43-file database. However, D506 provided a broader provincial distribution and captured a more dynamic treatment timeline. Conclusion & Recommendations: To assess the D506 system as a replacement for R506, key factors such as usability, performance, real-time data integration, and cost-efficiency must be evaluated. If D506 demonstrates superior accuracy, efficiency, and public health impact, it could offer a more responsive and integrated surveillance system.