Reliable surgical site infection surveillance with robust validation is required

We would like to thank Lamagni and her colleagues from the Health Protection Agency for their interest in our paper. While they state in their letter that post discharge surveillance (PDS) is not used for benchmarking, and therefore Trusts which conduct PDS are not penalised, we should like to point out that inconsistencies were also found among in-patient and readmission data which are used for benchmarking .Therefore Trusts could be penalised. They also claim that the national surveillance programme, which collects in-patient and readmission data, produces reliable data. However, one of the authors of the Lamagni letter appears to contradict this in the January 2013 edition of the Journal of Infection Prevention (JIP)1. In the JIP article, Wilson discusses various data collection methods, such as prospective, active, passive, staff reporting, telephone follow up of laboratory reports only, liaison with ward staff and case note review, and states how each of these methods has a ‘major effect’ on reported SSI rates. All of these data collection methods are permissible in the current national surveillance programme, yet Wilson goes on to argue that a national surveillance system must prescribe data collection methods which minimise the risk of selection and measurement bias, thereby enabling comparisons between hospitals. Indeed, in effect supporting the claims of our paper, Wilson further states that reliable surveillance methods are desirable if data are to be trusted by surgical teams and also calls for robust validation systems.