Accuracy and quality of immunization information systems in forty-one low income countries

Objectives: To measure the accuracy and quality of immunization information systems in a range of low-income countries eligible to receive GAVI support.

Methods: The Data Quality Audit (DQA) uses a WHO validated, standard methodology to compare data collected from health unit (HU) records of immunizations administered with reports of immunizations at central level and to collect quality indicators of the reporting system. The verification factor (VF), as a measure of accuracy, expresses the proportion of immunizations reported at national level that can be tracked down to the HU. A VF of 80% or above entitles countries to receive additional GAVI financial support. Quality indicators are assigned points which were summed to obtain quality scores (QS) at national, district and HU levels. DQAs included here were conducted between 2002 and 2005 in 41 countries, encompassing 1082 primary healthcare units in 188 randomly selected districts.