The use of epidemiological tools in conflict-affected populations: open-access educational resources for policy-makers

Table of Contents

1. Welcome
2. Introduction: Epidemiology in crises
3. Ethical issues in data collection
4. Need for epidemiologic competence
5. Surveys - Introduction
6. Surveys - Description of sampling methods
7. Surveys - Sampling error, bias, accuracy, precision, & sample size
8. Surveys - Resources required for surveys
9. Surveys - Critiquing survey reports
10. Surveillance - When to do surveillance
11. Surveillance - Methods
12. Surveillance - Common problems
    1. Inherent problems
    2. Incomplete reporting
    3. Biases from the health system
    4. Changes in the surveillance system
    5. Denominator problems
    6. Assessing quality of data
13. Programme data
14. Rapid assessment
15. Mortality - Indicators and their measurement
16. Mortality - Data sources
17. Mortality - Interpretation and action
18. Nutrition - Introduction and background
19. Nutrition - Indicators and their measurement
20. Nutrition - Data sources
21. Nutrition - Interpretation and action
22. Health services
23. Vaccination programmes
24. Water supply, sanitation, and shelter
25. Violence
26. Presentation of results
27. Formulating conclusions and recommendations
28. Dissemination and action

Assessing quality of data

(go to Outline)

Overall, surveillance can be more timely and flexible than other data collection methods, but interpretation of the resulting data must be done carefully. Before reaching conclusions you should know a great deal about the surveillance system producing the data, such as:

• Who reports the data? At what health facilities?
• How complete is the reporting?
• Approximately what proportion of patients with the disease actually seek medical care in reporting facilities?
• What proportion of eligible health facilities report data regularly? Has this changed during the time period of interest?
• Were there any changes in the surveillance system or case definition during the time period of interest?
• Have there been any changes in the denominator used to calculate incidence rates?