Keywords: Sensitivity, evaluation, electronic medical records, influenza, primary healthcare

Background:

In Belgium, the semi-automated COVID-19 Barometer in General Practices (cBGP) provided Influenza-Like Illness (ILI) data as an early marker for COVID-19 activity. Formal evaluation of this code-based tool with the established ILI surveillance based on the Sentinel General Practitioners network (SGP) is needed to progress towards real-time data and greater General Practitioners (GPs) participation.
An assessment of the ILI clinical syndrome, reported in the questionnaire-based SGP system, and the related diagnostic code registration in GPs’ medical software was not yet carried out in Belgian primary care.

Research questions:

To what extent is the capture of ILI cases comparable between cBGP and SGP systems to ensure accurate disease surveillance?

Method:

An observational study is conducted on data from 2021 to 2024.
For each week of analysis, practices that reported ILI cases in cBGP and SGP systems are included. A weekly participation of at least 3 days is required for cBGP data, whereas for SGP data, participation is assumed to cover all working days.
The daily diagnostic coding percentage of practices involved in cBGP, is taken into account for quality purposes, with a minimum threshold set at 70%.
A descriptive comparison of case definitions and factors potentially impacting cases capture, is performed. Additionally, a regression analysis is undertaken on the number of ILI cases registered in both systems by the same practices.

Results:

The number of practices participating in both systems decreased over the study period: 48 practices (in 2021), 39 practices (in 2022), 29 practices (in 2023) and 16 practices (in 2024). Complete results will be available by the time of the conference.

Conclusions:

The results will establish whether there is a correspondence between the number of cases based on diagnostic codes and on clinical case definition of ILI in Belgian general practices, while shedding light on the reason why discrepancies might exist.

Points for discussion: