Data quality of reported child immunization coverage in 194 countries between 2000 and 2019

Area of Science:

• Public Health
• Global Health
• Data Science

Background:

• Analyzing immunization coverage data is vital for national programs and global initiatives like Immunization Agenda 2030.
• Assessing data quality ensures reliable monitoring and effective decision-making in public health.

Purpose of the Study:

• To evaluate the quality of reported child immunization coverage data across 194 countries from 2000 to 2019.
• To identify trends and regional variations in data quality for key vaccines.

Main Methods:

• Analysis of child immunization coverage data reported to WHO and UNICEF for Bacillus Calmette-Guérin (BCG), DTP (diphtheria-tetanus-pertussis), and MCV1 (measles-containing vaccine).
• Assessment of data completeness, consistency, integrity, and congruence, with data quality flags assigned for anomalies.
• Application of generalized linear mixed-effects models to estimate the probability of data quality flags globally and by region over time.

Main Results:

• Globally, 18.2% of immunization coverage data reported between 2000-2019 had quality flags.
• The Americas region showed the highest probability of data quality flags (29.7%), while South-East Asia had the lowest (6.3%).
• A significant global decline in the probability of data quality flags was observed (-5.1% annually), with notable improvements in Africa, Europe, and the Americas.

Conclusions:

• The quality of global immunization coverage data has generally improved over the past two decades.
• Progress in data quality has not been uniform across all countries and regions.
• Continued joint efforts are necessary to ensure all countries collect, report, and utilize high-quality immunization data for public health action.