Early results from the Northland immunisation register.
A controlled trial to determine the effects of introducing a centralised, computerised immunisation register commenced in Northland in May 1985. All infants born since 1 January 1985 have been registered on the Health Department's mainframe computer and assigned to either control or test groups. This birth information has been used to study two interventions aimed at increasing immunisation levels in the experimental group. The first involves sending to general practitioners lists of infants due for immunisation, and the second sending immunisation reminder cards to parents. Results show significant differences in immunisation levels between test group infants and comparable controls: an 18.2% increase for the six week immunisation, a 16.7% increase for the three month immunisation, and a 4.7% increase for the five month immunisation. A user survey has shown a high degree of acceptance by GPs and practice nurses. The pilot scheme will continue through 1986, and will be used over this period to improve acceptability to users and assist in planning a possible national computerised immunisation information system.