The Camberwell Assessment of Need (CAN) is a standardized measure for assessing the needs of people experiencing severe and/or enduring mental health problems. It covers a wide range of health and social needs, and incorporates staff, service users and informal carer perspectives.The CAN was developed for use by three groups:
1. Mental health workers involved in planning care for people with severe mental health problems.
2. Mental health service users in rating their own needs.
3. People wanting to evaluate mental health services.
The first edition of the CAN was published in 1995 by the Section of Community Psychiatry (PRiSM) at what is now called the Institute of Psychiatry, Psychology and Neuroscience in London, EnglandReference Phelan, Slade and Thornicroft1. The accompanying book was published in 1999 by Gaskell, the imprint of the Royal College of PsychiatristsReference Slade, Loftus, Phelan, Thornicroft and Wykes2.
The initial goal in developing the CAN was to develop a needs assessment measure that would meet the needs of the National Health Service and Community Care Act (1999). The Act defined need as: ‘The requirements of individuals to enable them to achieve, maintain or restore an acceptable level of social independence or quality of life’. This understanding of need represented a departure from the previous conceptualisation of need as a normative concept that is defined by expertsReference Bradshaw and McLachlan3. The specific extension of including the perspective of service users about their own needs was an innovation at the time, and laid the basis for subsequent shifts in mental health practice towards increased service-user involvement and patient-focussed care.
Experience from two decades of using the CAN has identified minor changes to make in publishing this 2nd edition.
Refinements to the CAN 2nd Edition
The CAN assesses 22 domains of health and social needs, shown in Table 1.1.
|3||Looking after the home|
|8||Information on condition and treatment|
|10||Safety to self|
|11||Safety to others|
Changes from the 1st Edition
The Dependents domain was called Childcare in the 1st edition. This change has been made to include a wider range of dependents reflecting changes arising from an ageing society.
The Digital communication domain was called Telephone in the 1st edition. This change has been made to include a wider range of digital approaches to communication, including social media.
The anchor points for both these domains have been refined to reflect these changes.
The needs of the individual can be rated from three perspectives: service user (i.e. self-rated), staff (i.e. their clinician or worker) and informal carers (e.g. their family member). Each of these ratings relates to the needs of the service user, so note that the informal carer perspective is not about the carer’s needs.
For each domain, a need rating is made using the ratings shown in Table 1.2.
|N||No need||No or only minor problem, with no help needed|
|M||Met need||No or only minor problem due to help given|
|U||Unmet need||Current serious problem|
|?||Not known||Do not know or would prefer not to say|
Changes from the 1st Edition
When first published, the need rating scale for CAN was 0 = No need, 1 = Met need and 2 = Unmet need. The use of numbers for what is categorical data has proved misleading, with some studies wrongly analysing the scores as ordinal or interval data, e.g. allocating two points for each unmet need and one point for each met need to produce a sum score for level of need. To make it clear that the need rating is categorical data on a nominal scale, the 2nd edition uses letters rather than numbers for the rating.
The most common total scores calculated from the need rating are shown in Table 1.3.
|Unmet need||Number of need domains rated U||0 (no unmet needs) to 22|
|Met need||Number of need domains rated M||0 (no met needs) to 22|
|Total needs||Met need + unmet need||0 (no needs) to 22|
The service-user rating of unmet need has emerged as the most empirically important score, as discussed in Chapter 3.
Four versions of the CAN have been developed:
1 CAN Short Appraisal Schedule (CANSAS)
A version that assesses the presence of a need in the 22 CAN domains from any of service user, staff or informal carer perspectives. CANSAS has emerged as the most useful CAN version for most clinical and research uses.
2 CANSAS – Patient (CANSAS-P)
A self-rated version of CANSAS, which can be self-completed with or without support. CANSAS-P is the CAN version to use where service users are self-rating their needs. It was developed independently and with permission by Glen Tobias and Tom Trauer in Australia.
3 CAN – Clinical (CAN-C)
A full assessment of health and social needs designed for clinical use. For each of the 22 CAN domains, CAN-C assesses the need rating, help received from informal carers and from services, help needed from services and the service user’s views about support needed, along with space to record a domain-specific action plan.
4 CAN – Research (CAN-R)
A full assessment of health and social needs designed for research use. For each of the 22 CAN domains, CAN-R assesses the need rating, help received from informal carers and from services, help needed from services and satisfaction with the type and amount of help received.
The 2nd edition of all four versions are described in this book.
Since the English-language version was developed, the CAN has been translated into 30 languages: Afrikaans, Cantonese, Czech, Danish, Dutch, French, German, Greek, Hebrew, Hindi, Hungarian, Icelandic, Indonesian, Italian, Kannada (India), Lithuanian, Malaysian (Bahasa), Maltese, Mandarin (mainland China), Mandarin (Taiwanese), Norwegian, Polish, Portuguese, Portuguese (Brazil), Romanian, Spanish, Swedish, Turkish, Vietnamese and Xhosa. Contact details for CAN translators are listed on the CAN website (researchintorecovery.com/can).Variants of the CAN have also been published, and are in widespread use for other populations:
people with learning or intellectual disabilities: CAN for Developmental and Intellectual Disabilities (CANDID)Reference Xenitidis, Slade, Bouras and Thornicroft6, Reference Xenitidis, Thornicroft and Leese7
forensic patients: CAN – Forensic (CANFOR)Reference Thomas, Harty, Parrott, McCrone, Slade and Thornicroft8, Reference Thomas, Slade and McCrone9
mothers and pregnant women with mental health problems: CAN – Mothers (CAN-M)Reference Howard, Slade, O’Keane, Seneviratne, Hunt and Thornicroft10, Reference Howard, Hunt and Slade11
people in disaster relief situations: Humanitarian Emergency Settings Perceived Needs (HESPER) scaleReference Semrau, van Ommeren and Blagescu12
Several of these variants are also being updated with 2nd editions.
This book is intended for people who are currently using or considering using the CAN. In Chapter 2, the development of the CAN and its psychometric evaluation by multiple independent research groups from many countries is described. Chapter 3 is new to the 2nd edition, and summarises 20 years of international research using the CAN. Chapters 4 to 7 describe the four versions of the CAN: CANSAS, CANSAS-P (new to the 2nd edition), CAN-C and CAN-R. Each chapter is intended to be self-contained, which results in intentional duplication within Chapters 4 to 7. Chapter 8 covers training approaches for using CAN, and Chapter 9 addresses frequently asked questions.
The appendices include all four versions in formats suitable for scanning, along with summary score sheets for CAN-C and CAN-R. All four versions can also be downloaded from researchintorecovery.com/can. Training vignettes and the original psychometric evaluation of the CAN are also included.