Integrating primary and secondary care: the case of Christchurch South Health Centre.

AIMS To study health services utilisation linkages and methodological issues in integrating primary and secondary care services for a defined general practice population (Christchurch South Health Centre, CSHC). METHODS The Centre supplied national health index (NHI) linked data on date of birth, gender and community services card (CSC) status for 10,174 patients, and data on primary care. Secondary care providers supplied NHI linked data on specialist outpatients, emergency department usage for 1996 to 1998, and waiting lists. The Health Funding Authority (HFA) supplied NHI linked data on inpatient/daypatients for 1996 and 1997. Data were also obtained relating to community support services and long-term care. Rates of hospital utilisation for the Centre's population were standardised for comparison with national and Christchurch figures using age, gender and CSCs. Overall per capita expenditure was calculated for this population. RESULTS Patients with CSCs constituted 31.2% of the practice population, but generated 60.8% of bed-days. Patients with high use health cards (HUHCs) constituted 8.6% of the population, but generated 42.4% of bed-days. This group was at high risk of hospitalisation over a wide range of disease categories. Standardised rates of hospital utilisation were significantly lower for the Centre's older patients, especially for bed-days, than both national and Christchurch figures. Only a small proportion of referrals to specialist outpatients, 28.2% in 1998, was from the Centre's general practitioners (GPs), the remainder being generated internally within the specialist services. The overall expenditure per capita on the Centre's population was $1012, which was substantially less than expected in comparison with national figures. CONCLUSION The study demonstrates the importance of primary care factors in the utilisation of secondary care, especially acute hospitalisation in older patients. This needs further study as it could provide important insights into ways of reducing acute admissions. If there is to be more effective management of the primary/secondary care interface, more research and development effort is needed into the characteristics of patients at high risk of referral and admission, and how inappropriate secondary care can be averted.