Peshawar, the capital of Khyber Pakhtunkhwa (KP), along with the adjacent Federally Administered Tribal Areas (Fata), as well as the adjoining Nangarhar province of Afghanistan, have been declared a polio-endemic geographical block by the World Health Organisation.
The intervention started in each geographical block after the baseline investigations.
Using the random number generator in the statistical package Stata (version 9), and after stratification by geographical block (the administrative unit above the village), one author (ED) randomly selected 30 of the 134 study villages to receive intervention A and 30 to receive intervention B. The 74 remaining villages were control villages and received no additional intervention.
However, direct comparisons cannot be made, since the latter emitted higher dioxin levels and has been studied at a finer geographical level (blocks), with a different (case-control) design.
Models contained the variable diagnosis (block 1), immigrant generation and geographical origins (block 2), and perceived discrimination and denial of resources (block 3).
Usually, cluster sampling involves selecting participants only from a limited number of defined geographical areas (eg, blocks, streets or parts of villages, or perhaps schools) that are themselves chosen randomly.
Many studies employed some form of cluster sampling, usually selecting participants from a limited number of defined geographical areas (e.g., blocks or streets, or parts of villages), themselves chosen randomly.
Per district, two blocks or geographical units were selected.
Sexual networks do not strictly follow geographical boundaries and the blocks for implementation were not contiguous.
These should contain geographical features such as: blocks, plots, constructions, water accumulations, relief and vegetation, and they should be used jointly with geodesic coordinates which could be provided by the global positioning system (GPS) and spatial statistical software [ 12].
