Many surveillance methods for nosocomial infections (NIs) have been put forward in the literature, and all have their advantages and disadvantages. Different surveillance methods are useful, depending on whether the objective of surveillance is only to increase sensitivity to infection control problems and to identify areas with possible infection control problems; to confirm a possible infection control problem through comparison with other units or departments; or to use surveillance data for identifying the sources of infections. Furthermore, time effectiveness is a major point in selecting the most appropriate method, particularly the method for case identification. In units or departments with a high level of NI, even highly time-consuming surveillance methods may be ultimately time-effective; in units or departments with a lower level of NI, the time-effectiveness depends on the time necessary for case identification. Close liaison with staff in the units is a sine qua non for the success of all surveillance activities.

Using KISS data for internal orientation, it is possible to note important differences between ICUs when interpreting infection rates; some initial examples of successful use of surveillance data for the reduction of infection rates are already available. However, the use of such data for external assessment is not possible, because external observers are often unable to fully consider important factors in the interpretation of infection rates.

The KISS reference data can help in assessing one's own SSI rates. A prerequisite is surveillance according to the KISS protocol.

The project has reached high interest in Germany and animated more ICUs to take part or to apply the same method in order to use the reference data for comparison.

These definitions of clusters and outbreaks can only provide an estimate of the real number of cases. However, through the targeted identification of ICUs with endemic and epidemic MRSA problems and subsequent strict measures to prevent the spread of MRSA within these ICUs, it may be possible to retain, or even reduce, the present level of MRSA infections in Germany.