National Health Account 2007-2008

Kenya is divided into eight administrative provinces. The provinces are in turn subdivided into 70 districts. Each district is subdivided into divisions while the divisions are split into locations and finally each location into sublocations.

During the 1999 population census, each sublocation was subdivided into smaller units called enumeration areas (EAs). Kenya has about 62,000 EAs. The EAs provided census information on households and population. This information was used in the design of the National Sample Survey Evaluation Programme (NASSEP) IV master sample with 1,800 selected EAs.

The cartographic records for each EA in the master sample were updated in the field, one year preceding the NHA survey. The 1,800 clusters were distributed into 540 urban and 1,260 rural clusters.

The province provided a natural stratification of the population. The six major urban centres Nairobi, Mombasa, Kisumu, Nakuru, Eldoret, and Thika were further substratified into five socioeconomic classes based on incomes to circumvent the extensive socioeconomic diversity inherent in them as follows: upper, lower upper, middle, lower middle and lower; this improved the precision of estimates due to reduced sampling variation.

It was estimated that 8,844 households would be sufficient to provide estimates both at provincial and national levels as well as disaggregation to urban and rural components of the country. This sample was to yield 6,060 interviews in the rural and 2,784 in the urban clusters (Table 2.2). This was to be achieved through coverage of 737 clusters (505 rural and 232 urban clusters).

Twelve households were to be covered in each cluster. The method of proportional allocation was used in assigning the sample households to the provinces and districts. The count of the households was transformed to the square root of the census households to avoid under-representing the smaller districts.