[Clinical research and data collection during the investigation: Influence of a dedicated staff]

In clinical research, the recourse to a staff dedicated as CRA with the investigator is common practice to facilitate the work of collection and limiting the missing data (MD). We, therefore, looked for the interest of the recourse of such personnel to data collection.

MD were classified according to five categories: clinical, para-clinical, treatment, adverse events (serious) and others. Studies were separated in two designs, one-off studies during a single visit (so-called "no follow") and studies on the duration and including several visits (say "with follow"). Similarly, studies were differentiated according to their type of collection "Without ARC" if the data were collected by an investigator, and studies "With ARC".

The presence of a CRA can reduce the number of MD whatever their type (Student test: P<0.0001): With CRA mean of MD is 4.8%±8.4% and Without CRA mean of MD is 22.1%±17.0%.

The delegation of data collection to a staff dedicated reduces significantly the percentage of missing data.