Abstract
Thailand is facing air pollution problems from PM2.5 exceeding standard levels every year
in Health Region 8 (particularly in Nakhon Phanom and Nongkai provinces), which has been
significantly affected. This study aimed to evaluate the PM2 . 5 surveillance system in Nakhon
Phanom and Nongkai provinces both qualitatively and quantitatively to develop policies and
operational guidelines and to serve as a case study for Health Region 8. This research employed
a mixed-method approach by conducting in-depth interviews with public health officials and
stakeholders and reviewing medical records of patients suspected of PM2.5 -related diseases at
2 provinces between October 1, 2020, and March 31, 2023.
The qualitative results found that the surveillance system has high acceptance due to
public concern over air pollution. The system is appropriately simple and flexible, but unclear
diagnostic criteria for PM2.5 - related diseases affect data analysis and accuracy. Nakhon Phanom
province, the quantitative results showed that out of 485 medical records meeting the ICD-10
criteria, 4 4 2 matched the reporting definitions, and 3 5 5 matched the disease definitions.
The system has high coverage (90.70%) but a moderate positive predictive value (76.30 % ) .
No clear correlation was found between PM2.5 levels and the number of patients, possibly due to
other factors affecting respiratory diseases. Nongkai province, a review of 345 medical records was
conducted, with 182 records meeting the definition of a patient. The sensitivity was 100%, and
the positive predictive value (PPV) was 53.08%. The data completeness for age, gender, and
nationality was 100%, while ICD-10 code completeness was 98.84%. The accuracy of the data for
age, gender, nationality, and ICD-10 codes was 97.97%, 92.46%, 98.26%, and 94.78%, respectively.
Additionally, the data for age, gender, and service date were representative.
In conclusion, the PM2.5 surveillance system in both provinces operate at a satisfactory
level with high coverage and data accuracy. However, the diagnostic criteria related to PM2.5
should be improved. These enhancements can increase the system's potential and improve
public health outcomes.
