The Camberwell Assessment of Need: the validity and reliability of an instrument to assess the needs of people with severe mental illness

Abstract

Background: People with severe mental illness often have a complex mixture of clinical and social needs. The Camberwell Assessment of Need (CAN) is a new instrument which has been designed to provide a comprehensive assessment of these needs. There are two versions of the instrument: the clinical version has been designed to be used by staff to plan patients' care; whereas the research version is primarily a mental health service evaluation tool. The CAN has been designed to assist local authorities to fulfil their statutory obligations under the National Health Service and Community Care Act 1990 to assess needs for community services.

Method: A draft version of the instrument was designed by the authors. Modifications were made following comments from mental health experts and a patient survey. Patients (n = 49) and staff (n = 60) were then interviewed, using the amended version, to assess the inter-rater and test-retest reliability of the instrument.

Results: The mean number of needs identified per patient ranged from 7.55 to 8.64. Correlations of the inter-rater and test-retest reliability of the total number of needs identified by staff were 0.99 and 0.78 respectively. The percentage of complete agreement on individual items ranged from 100-81.6% (inter-rater) and 100-58.1% (test-retest).

Conclusions: The study suggests that the CAN is a valid and reliable instrument for assessing the needs of people with severe mental illness. It is easily learnt by staff from a range of professional backgrounds, and a complete assessment took, on average, around 25 minutes.