A chickenpox surveillance evaluation in the 2nd district group of public health centers in Bangkok area under the Bangkok Metropolitan Administration, Fiscal Year 2017–2019

Abstract

Background: Chickenpox is one of common infectious diseases occurring in Bangkok. During the fiscal year 2017- 2019, the incidence rate of chickenpox from national surveillance system (R506) of the public health centers in the 2nd district group under the Bangkok Metropolitan Administration were much lower, compared with incidence rate in Bangkok. The study aims to examine the reporting process, to evaluate quantitative and qualitative attributes, and to provide recommendations for improving chickenpox surveillance system in the 2nd district group of public health centers in Bangkok.
Methods: We gathered data from cases reported in national surveillance system (R506) and medical records according to the diagnosis defined by ICD-10-TM during October 1, 2017 to September 30, 2019. Quantitative attributes that we assessed included sensitivity, positive predictive value (PPV), data quality, representativeness and timeliness; however, we interviewed the related stakeholder to examine acceptability, simplicity, flexibility, stability and usefulness as qualitative attributes.
Results: Of the medical records reviewed, 81 patients met the chickenpox definition of suspected case and 37 cases were reported via R506. It is found that one patient who did not meet the case definition but was reported. The sensitivity and PPV were found to be 45.68% and 97.37%, respectively. Accuracy of gender was 100%; while, accuracy of name, surname, and age were over 84%. Accuracy of onset date was quite fair with 76.32%; however, accuracy of treatment date and report submission date were as high as 9 7 . 3 7% . We also found that the representativeness was quite good in terms of gender and age. Most of the cases (92%) were reported timely within 48 hours. For qualitative study, most of the personnel accepted the surveillance system. The surveillance system seemed to be flexible and useful.
Conclusions: Chickenpox surveillance system evaluation in the 2nd district group of public health centers in Bangkok area under the Bangkok Metropolitan Administration had low sensitivity, possibly due to lack of surveillance report monitoring system and paper-based medical records. The system had good PVP, accuracy, representativeness and timeliness. In terms of the qualitative data, although the acceptability was good, the system to determine whether any patient has not been reported should be developed.