Residence coding in the Hospital In-Patient Enquiry (HIPE) system: significantly worse than anticipated

Abstract

Analysis was conducted of the patient residence geocoding of all E-code (external cause) discharges on the Hospital In-Patient Enquiry system for the calendar year 1996 from Limerick's two acute hospitals (one public, one private). The results indicate a substantial level of error, even at county and county borough level. Some 21 percent of the 1383 patients attributed to Limerick County Borough were wrongly assigned to this area. Only marginal differences were reported between the public and private hospitals, with the private hospital managing a slightly higher accuracy rate. The implications of this finding are significant for any analysis of spatial patterns of health care use. Particular care needs to be taken in relation to HIPE patient residence coding relating to any of the county boroughs in Ireland. A software geocoding engine urgently needs to be introduced into the HIPE system capable of geocoding patient addresses at least to district electoral division (ded)/ward level, and ideally to point location.