Measuring coverage in MNCH: design, implementation, and interpretation challenges associated with tracking...

Area of Science:

• Public Health
• Epidemiology
• Survey Methodology

Background:

• Vaccination coverage is a key public health indicator.
• Surveys are commonly used to measure vaccination coverage, especially in low- and middle-income countries.
• Current survey methods face challenges impacting data accuracy.

Purpose of the Study:

• To identify and discuss challenges in measuring vaccination coverage using surveys.
• To highlight the impact of biases on coverage estimates.
• To propose recommendations for improving survey-based vaccination coverage measurement.

Main Methods:

• Analysis of common biases in vaccination coverage surveys: selection bias and information bias.
• Discussion of factors contributing to these biases, including sampling frames, field procedures, data transcription, and recall.
• Consideration of serological assays as a complementary but distinct method.

Main Results:

• Selection bias, often due to inaccurate sampling frames or field procedures, tends to inflate coverage estimates.
• Information bias arises from misclassification of vaccination status, exacerbated by reliance on guardian recall and complex immunization schedules.
• Serosurveys assess immunity but do not directly validate coverage estimates.

Conclusions:

• Improving recording tools and practices is essential for accurate vaccination data.
• Surveys must incorporate best practices in design, implementation, and analysis to mitigate biases.
• Enhanced survey methodologies are needed to ensure reliable vaccination coverage measurement for public health.