Validity of reported vaccination coverage in 45 countries.

Area of Science:

• Public Health
• Epidemiology
• Health Services Research

Background:

• Accurate monitoring of national health programs, particularly vaccination coverage, is crucial for child health interventions.
• The diphtheria-tetanus-pertussis vaccine (DTP3) coverage rate is a key indicator for assessing child health programs.
• Assessing the accuracy of officially reported DTP3 coverage rates is essential for reliable program evaluation.

Purpose of the Study:

• To evaluate the accuracy of officially reported national diphtheria-tetanus-pertussis (DTP3) vaccine coverage rates.
• To compare official DTP3 coverage data with estimates from household Demographic and Health Surveys (DHS).
• To assess the validity of official data for tracking changes in vaccination coverage over time.

Main Methods:

• Compared official DTP3 coverage data with DHS household survey data from 45 countries (1990-2000).
• Adjusted DHS data for valid vaccinations using a probit model with sample selection to correct for bias.
• Analyzed survey bias and discrepancies between official reports and DHS estimates.

Main Results:

• Officially reported DTP3 coverage rates were consistently higher than those from DHS household surveys.
• The discrepancy between reported and survey data increased with higher reported coverage rates.
• Time-trend analyses revealed no correlation between changes in reported coverage and changes indicated by household surveys.

Conclusions:

• The validity of officially reported DTP3 coverage data for measuring changes over time is questionable.
• Household surveys provide a valuable tool for validating service provider data on vaccination coverage.
• Future health intervention monitoring strategies must prioritize rigorous assessment of data source validity.