Comparison of three rapid household survey sampling methods for vaccination coverage assessment in a peri-urban setting in Pakistan

Household surveys are essential for vaccine coverage monitoring in developing countries. The World Health Organization (WHO) Expanded Program on Immunizations (EPI) cluster survey design has been a default choice for decades. This study compared the coverage estimates and time efficiency of EPI sampling design and two alternative methods: the compact segment sampling and innovative grid-based geographical information system (GIS) sampling.

Key Messages:

1. Compared with the traditional EPI cluster survey, the other two methods produced similar vaccine coverage estimates in a peri-urban setting in Karachi, Pakistan
2. Since the traditional EPI surveys did not correctly account for the sampling weights, the design effects were underestimated. The other two methods had shown higher design effects and thus require a larger sample size for the same precision.
3. More methodologically rigorous sampling designs are preferred in future household surveys. Surveyors need to evaluate and be prepared for the potential increase in sample size requirements and implementation costs.