[Sampling procedure for a survey of an interventional study on acute respiratory infections]

A description is made of the methodology used for obtaining a sample made up of 500 children under 5 years and 500 adults 65 year old and more, in order to carry out an intervention study on acute respiratory tract infections in an urban zone in Havana City and in a rural zone in Matanzas province, where different intervention stops will be taken with regards sanitary education about management of acute respiratory tract infections for the population and training for primary care medical personnel. We show the way the selected sample fits was planned with a very homogeneous distribution in the 8 areas under study, which allows for great reliability in the results.