It is important therefore that the reforms are structured to foster co-ordination rather than fragment care further. Such policies do not of themselves facilitate co-ordination, and can present real or perceived barriers to integration. Choice and competition in primary care, and the resulting loss of a geographical responsibility for population health, have the potential to exacerbate fragmentation of care and impede the ability of local agencies to work together to provide seamless health and social care in the most cost-effective way - especially in urban areas with a multiplicity of providers. The risks of fragmentation and poor care co-ordination are greatest for older people, complex and frail patients, and people with mental health problems; these are also the groups least able to navigate the system and exercise informed choice, hence they can be disenfranchised from the reform process.