Population morbidity screening--practical methodology for small populations.

During a study of the health status of children in rural Nigerian communities a gross lack of fit was observed between the sample and the growth attainment standards derived from local longitudinal data. The degree of misfit was greater in children over the age of 3 years and deteriorated with age thereafter. A very high incidence of tuberculosis seemed to be responsible for the deviation in the sample. A simple practical methodology is presented, suitable for dealing with small samples: this is an application of the established Z value analysis which may easily be used by a wide variety of personnel.