The case for catchment areas for mental health services

mental health services. In brief, it is argued that community mental health services are still in many areas poorly developed (Audit Commission, 1994; Faulkner et al, 1994), and that catchment areas are necessary but not sufficient for their fuller realisation. 250,000 to Sweden with 25-50,000. Italy most comprehensively adapted the concept by virtue of Law 178 which established sectors of 50-200,000 population. Sectors are not only a concept of health services. In each local area in Britain, housing, social services and the police have geographically denned areas of responsibility. In planning services for the severely mentally ill it is necessary to ensure improved outcomes by implementing effective interventions in the following key areas: housing, welfare benefits, physical health, daily living skills, work and education. This can best be achieved by


Graham Thornicroft, GÃ©raldineStrathdee and Sonia Johnson
The establishment of mental health teams which take responsibility for small geographical catchment areas has been a fundamental element in the planning of community services in most Western European countries over the last decade.This idea is challenged in the companion paper in this issue of Psychiatric Bulletin which refers to catchment areas as a "relic of the past".1992).The three primary arguments for catchment areas are that they fix responsibility for care with named staff, and that they encourage continuity of care and that they facilitate effective inter-agency working.Responsibility for each patient requiring a service is allocated to a specified team, which can make population and patient needs assessments, so minimising the number of patients lost to follow-up (Wing, 1992).In addition, the development of alternative types of sector team allows empirical investigation of their cost-effectiveness and acceptability.Where staff in the community agencies know each other and meet face to face, working to a common agenda services development is likely to proceed faster.
Where evaluations of sectorisation have been reported, the findings are favourable.In Nottingham, for example, Tyrer et al (1989) found reductions in the number of admissions (5%), duration of admissions (4%), and use of in-patient beds (38%).Similarly in Sweden, Hansson (1989) recorded falls in the number of admissions (20%), beds days used (40%), and compulsory admissions (25%).The Mental Health Task Force London Study (Cochrane et al 1994) highlighted the difficulties in planning community services where there were not co-terminous boundaries between the three key agencies (health, housing and social services).
Small geographical catchment areas are now the norm for adult mental health services in England and Wales.In a recent survey, 199 district health authorities were contacted.Most (87%) responded and of these 81% (n=140) reported that they had sectorised their mental health services (Johnson & Thornicroft, 1993).Sectorisation had started in 1959, with 1985 as the median year.In 63% (n=86) of sectorised districts, a single team in each sector provides both continuing care and acute services, while in 10% (n=13) the sector has two teams for these separate functions.The median sector population was 60,000, with a mean of 70,600.

Factors influencing catchment area boundaries
The division of a district into smaller catchment areas is influenced by many considerations (Table 4).The most important issues are the rural or urban nature of the area, the presence of a river or other natural structure which impairs access; the need to achieve co-terminosity with either a social services boundary or general practice locations; and the division of the total district into areas which are manageable for the local mental health teams.
The primary-secondary care interface The most serious arguments against rigid catchment areas arise where primary and secondary care boundaries are not co terminous.In this case there may be concern from family doctors, patients and their carers that a sectorised service may reduce their choice for a preferred local psychiatrist, and may promote generalist rather than specialist services.Primary care attachments of specialist staff can go some way towards addressing this dilemma by assessing all patients referred by practice staff, and only referring on to other catchment area teams those few patients who require ongoing specialist care.Indeed, a flexible application of catchment area boundaries is necessary for the system to work for the advantage of patients.In some cases the importance of an individual staff-patient relationship is such that it should override the strict application of what is an administrative convenience designed to improve the quality of service to most but not all patients.
In some rural areas and in smaller towns the ideal arrangement of co-terminous social services, and primary and secondary health services may occur.But in many metropolitan areas borough and primary care boundaries inter-weave.To rely on a primary care list alone for secondary care teams would potentially render some patients who are homeless, unregistered or who do not attend their GPs lost to contact, and this is more likely to occur for the more severely mentally ill (Harrison et ai, 1994).
Current trends in British mental health services are clear: progressive reductions of long-term beds in hospital (Davidge et al, 1993), policies which guide staff to target services on the most severely mentally ill (Department of Health, 1993), and continuing widespread concern about cases in which continuity between services and across time has been inadequate (North East Thames and South East Thames Regional Health Authorities, 1994).One fundamental building block of the NHS.which has allowed a public health perspective to guide health services, has been the catchment area.Without this, a mosaic of smaller service providers may together fail to provide any service to many patients, as the example of some parts of the USA shows.It is therefore reasonable, at this stage of the development of mental health services, to target as the first priority the most severely disabled patients by using mental health catchment area teams, and, as a second priority, to support, through GP practice attachments, primary care staff with the other 90% of mentally ill patients who are not referred on to specialist teams.