SIR—The needs of older people are often multiple, complex and are at times experienced in combination, which require closely targeted services [1] and necessitate the collaboration of several professional groups. However, care has often been disjointed and compartmentalised [2]. One response to this has been a call for integration, between health and social care. Integrated care can operate at the organisational level, in terms of structures [3, 4] or the professional level, in terms of shared working arrangements, multidisciplinary teams and case management [5, 6]; an issue being that integrated structures, although conducive to inter-professional working, do not necessarily guarantee it [7].

Integration is assumed to produce benefits in terms of better co-ordination of services, better outcomes and greater efficiency [8]. Integration remains an aim pursued by successive governments [9]. Policies in several countries call for integration at the assessment stage; a key phase in terms of ensuring care closely matches older people’s needs [10, 11]. In England, examples are the single assessment process (SAP), offering a common structure through shared tools and processes [12], and the common assessment framework (CAF) for adults, advocating technical solutions for information sharing [13]. However, while evidence identifies potential benefits of integrating assessment information from different professionals [5, 14] and of more comprehensive geriatric assessment [15], there remains a need to examine the cost-effectiveness of such approaches to guide future policy.

We reanalysed data from a randomised controlled trial of integrated assessment between specialist clinicians and social services care managers in England [14] to offer evidence of the costs and benefits of integration. We evaluated the experiment’s impact on changes in functioning, admissions to care homes and use and costs of health and social services for frail older people at risk of entering care homes