Table 1.

Data categories and their definitions.

Category	Definition
Clustering and aberration detection algorithm	The kind of clustering and aberration detection algorithm used and implemented in the study.
Type of clustering algorithm	The type of algorithm used (spatial, temporal, or spatiotemporal algorithm).
Threshold	The type of threshold used to generate alarms and alerts in the study.
Design method	The design method used in implementing the system, such as prototype, participatory or joint application development, or agile or waterfall model.
Evaluation criteria	The criteria used to evaluate the algorithms.
Performance metrics	The performance metrics used to evaluate the algorithms, such as sensitivity, specificity, and positive predictive value.
Type of location	Locations used in clustering, including geolocation, postal codes, and counties; specifies the exact type of location used in the system.
Source of location	Where the type of location information was obtained.
Nature of location	State of the location as static or dynamic.
Visualization tool	The type of tool used to implement the visualization aspect of the system.
Display report	The type of visual displays (eg, graphs, maps, time series) implemented by the various systems in the study.
Design layout	The stages and processes used in the architectural design of the syndromic surveillance system (eg, a layout may consist of data acquisition, clustering and aberration detection, and visualization [21], or may include privacy-preserving mechanisms, machine learning techniques in processing the data, and other layers [24,25]).