Evaluation of a surveillance system

How can we measure a surveillance system?

Steps of an evaluation

  1. Plan the evaluation
    1. Understand the trigger
    2. Engage stakeholders
    3. Decide on attributes
  2. Perform the evaluation
    1. Start with a evaluation protocol
    2. Look at each attribute in its own way
  3. Propose an action plan

Typical triggers (1a)

  • Missed outbreak
  • Increased disease importance
  • Occurrence of new public health event
  • Cost saving
  • Requirement to evaluate (IHR)
  • New technology

Engage the stakeholders (1b)

  • Surveillance is a group effort
  • Not like a science project

Choose attributes (1c)

  • Depends on the trigger
  • Many attributes are costly

Balance of attributes (1c)

Evaluation protocol (2a)

  • Its similar to a study protocol
  • Important for coordination
  • Important part: Describe the system

Evaluate attributes (2b)

  • Sensitivity: Get gold standard
  • External completness: Capture-Recapture
  • Internal completeness: Data analysis
  • Timeliness: Data analysis
  • Usefulness: Survey

Propose an action plan (3)

  • An evaluation is objective oriented
  • It should focus on improving the system