Are hard-to-reach populations being reached with immunization services? Findings from the 2005 Papua New Guinea national immunization coverage survey.

Objective: To measure immunization coverage among children aged 12-23 months in Papua New Guinea (PNG) and to assess if and why there are differences between hard-to-reach and more accessible communities.

Methods: WHO cluster sampling methodology was employed to measure immunization coverage in PNG's four regions. Survey data were re-analyzed according to a local assessment of geographical accessibility indicated by census unit type: urban, rural and hard-to-reach.