The Health and Social Care Act 2012 will have "severe implications" for collecting and monitoring data about the health needs of the population in England, warn experts today.
In a paper published on BMJ, Professor Allyson Pollock, Professor Alison Macfarlane and Sylvia Godden argue that the new legislation will make it "extremely difficult" to monitor health inequalities and access to care locally or nationally.
The administrative structure of the NHS in England is currently based on resident populations of defined geographical areas. Under the new legislation, most health services will transfer to non-geographically based clinical commissioning groups (CCGs) that will be able to recruit patients living anywhere in England.
This, warn the authors, is likely to lead to erosion of data quality, accuracy, and completeness.
For example, responsibility for services such as childhood immunisation, HIV and sexual health, and mental health will be located in local authorities. Since local authority residents may be registered with any one of a number of different CCGs, the local authority will have to subcontract these services to a CCG, which could in turn outsource them to several providers.
Although it will be possible to compare differences between CCGs, "the instability of the denominator population will hinder accurate interpretation of the data," say the authors.
Cancer registries will also be affected, while increased outsourcing of care to private providers creates problems with the quality, completeness, and accuracy of coding of data, they add.
Finally, they argue that the transfer of resources and NHS staff to the private sector means that they will no longer be counted in NHS bed availability and workforce statistics, creating problems for long term planning.
They conclude: "The NHS is founded on the principle of comprehensive coverage. Equitable public health activity requires reliable information. The abolition of area based structures and the transfer of most responsibilities to non-geographically based CCGs, as well as some responsibilities to local authorities, undermines the availability of information and routine data required to monitor the comprehensiveness of the health service, inequalities in access, the resourcing of services, and outcomes of care.
Private income generation coupled with the loss of the NHS' population basis and responsibilities for comprehensive data collection and monitoring will make it almost impossible to take the action needed to tackle inequalities in health and in access to healthcare."