[Basic procedures in data registers and processing]

This paper describes the general principles that must be used as a frame of reference to identify the appropriate procedures for the management of data collected in large scale studies. It has two parts: 1) Data recording and, 2) data processing. In the first part (data recording), the various steps required for the preparation of forms and/or questionnaires and for the recollection of data are discussed. In the second part (data processing), the steps to achieve real quality control, proper coding and data entry for analysis are described. For the latter case, an outline of continuous general steps is proposed, and some statistical procedures commonly used for testing different hypotheses are identified. The overall process is illustrated through flow charts, emphasizing the fact that the processing and analysis of data, must be a continuous action which requires careful definition in the standard protocol of operations.