Chapter 3: Approaches to Surveillance


Chapter 3 describes some of the different methodological approaches used in the surveillance of congenital anomalies. Once the purposes of surveillance for a congenital anomalies programme have been established, the next steps are to:

  • Define the population under surveillance – population-based or hospital-based
  • Identify the area of surveillance, such as the geographical area of coverage
  • Determine approaches for identifying cases using case ascertainment methods, single or multiple data sources, and inclusion/exclusion criteria
  • Choose the core demographic or clinical variables for identifying cases based on the goals and objectives of the surveillance program
  • Select formats for documenting case descriptions on forms and within the coding system
  • Plan and implement data collection and management methods (e.g., using a protocol) to promote the gathering of accurate, high quality data
  • Analyse, interpret, and disseminate data using correct and systematic methods.


Watch videos on birth defects surveillance for population-based and hospital-based programmes.