For activity from 2011-12 onwards, HES users are advised to use the field RESLADST_ONS instead of RESLADST. This field contains a code that defines the county (first two characters) and local authority district (last two characters) of residence of the patient. It is derived from the patient's postcode in the field homeadd. Note that this field uses old-style geographical codes that were superseded in 2011 and are now no longer supported by ONS. The field RESLADST_ONS represents the local authority district of residence using codes from the current ONS geographical coding system. RESLADST is used in conjunction with CURRWARD (current electoral ward) to produce a unique value indicating the ward within a given district where the patient resided (ie because identical CURRWARD codes are allocated to many local authority districts, CURRWARD is meaningless in isolation). If the patient is resident within a Unitary Authority, the first two characters will be 00 (zero, zero) and the local authority component may not be useable.

resladst