A NOT QUITE AS QUICK BUT MUCH CLEANER ALTERNATIVE TO THE EXPANDED PROGRAM ON IMMUNIZATION (EPI) CLUSTER SURVEY DESIGN

Background. Although the Expanded Programme on Immunization (EPI) clus ter survey methodology has been successfully used for assessing levels of immunization programme coverage in developing country settings, ce rtain features of the methodology, as ii is usually carried out, make it a less-than-optimal choice for large, national surveys and/or surve ys with multiple measurement objectives. What is needed is a 'middle g round' between rigorous cluster sampling methods, which are seen as un feasible for routine use in many developing country settings, and the EPI cluster survey approach. Methods. This article suggests some fairl y straightforward modifications to the basic EPI cluster survey design that put it on a solid probability footing and render it easily adapt able to differing and/or multiple measurement objectives, without incu rring prohibitive costs or adding appreciably to the complexity of sur vey operations. The proposed modifications concern primarily the manne r in which households are chosen at the second stage of sample selecti on. Conclusions. Because the modified sampling strategy maintains the scientific rigor of conventional cluster sampling methods while retain ing many of the desirable features of the EPI survey methodology, the methodology is likely to be a preferred 'middle ground' survey design, relevant for many applications, particularly surveys designed to moni tor multiple health indicators over time, The fieldwork burden in the modified design is only marginally higher than in EPI cluster surveys, and considerably lower than in conventional cluster surveys.