Sampling the Maori population in the 2006/2007 New Zealand Health Survey

The 2006/2007 New Zealand Health Survey sample was designed to meet a range of objectives, the most challenging of which was to achieve sufficient precision for subpopulations of interest, particularly the indigenous Maori population. About 14% of New Zealand's population are Maori. This group is geographically clustered to some extent, but even so most Maori live in areas which have relatively low proportions of Maori, making it difficult to sample this population efficiently. Disproportionate sampling and screening were used to achieve sufficient sample size while maintaining low design effects.