The immunization data quality audit: verifying the quality and consistency of immunization monitoring systems

To evaluate the consistency and quality of immunization monitoring systems in 27 countries during 2002-03 using standardized data quality audits (DQAs) that had been launched within the framework of the Global Alliance for Vaccines and Immunization.

The consistency of reporting systems was estimated by determining the proportion of third doses of diphtheria-tetanuspertussis (DTP-3) vaccine reported as being administered that could be verified by written documentation at health facilities and districts. The quality of monitoring systems was measured using quality indices for different components of the monitoring systems. These indices were applied to each level of the health service (health unit, district and national).

The proportion of verified DTP-3 doses was lower than 85% in 16 countries. Difficulties in verifying the doses administered often arose at the peripheral level of the health service, usually as the result of discrepancies in information between health units and their corresponding districts or because completed recording forms were not available from health units. All countries had weaknesses in their monitoring systems; these included the inconsistent use of monitoring charts; inadequate monitoring of vaccine stocks, injection supplies and adverse events; unsafe computer practices; and poor monitoring of completeness and timeliness of reporting.

Inconsistencies in immunization data occur in many countries, hampering their ability to manage their immunization programmes. Countries should use these findings to strengthen monitoring systems so that data can reliably guide programme activities. The DQA is an innovative tool that provides a way to independently assess the quality of immunization monitoring systems at all levels of a health service and serves as a point of entry to make improvements. It provides a useful example for other global health initiatives.