The challenging nature of patient identifiers: an ethnographic study of patient identification at a London walk-in centre.

The correct identification of a patient's health record is the foundation of any safe patient record system. There is no building of a ;patient history', no sharing or integration of a patient's data without the retrieval and matching of existing records. Yet there can often be errors in this process and these may remain invisible until a safety incident occurs. This article presents the findings of an ethnographic study of patient identification at a walk-in centre in the UK. We offer a view of patient identifiers as used in practice and show how seemingly simple data, such as a person's name or date of birth, are more complex than they may at first appear and how they potentially pose problems for the use of integrated health records. We further report and discuss a dichotomy between the identifiers needed to access health records and the identifiers used by practitioners in their everyday work.