Quality assurance sampling for evaluating health parameters in developing countries - ARCHIVED

A typical goal of health workers in the developing world is to ascertain whether or not a population meets certain standards, such as the proportion vaccinated against a certain disease. Because populations tend to be large, and resources and time available for studies limited, it is usually necessary to select a sample from the population and then make estimates regarding the entire population. Depending upon the proportion of the sample individuals who were not vaccinated, a decision will be made as to whether the coverage is adequate or whether additional efforts must be initiated to improve coverage in the population. Several sampling methods are currently in use. Among these is a modified method of cluster sampling recommended by the Expanded Programme on Immunization (EPI) of the World Health Organization. More recently, quality assurance sampling (QAS), a method commonly used for inspecting manufactured products, has been proposed as a potentially useful method for continually monitoring health service programs. In this paper, the QAS method is described and an example of how this type of sampling might be used is provided.