I assume the trusts, who are responsible for delivering care, are responsible for implementing the guidelines. NHS England [English National Authority] has responsibility - i.e. as the Authority which commissions care via the trusts - and the body which oversees the NHS system in England - so I guess it will assist the trusts in implementing the guideline.
Ultimately it is the individual trusts which bear legal/financial responsibility if a claim is submitted alleging a patients care did not reflect the guidelines.
Not really my thing but
@CRG has a better grasp of this.
Not sure I have all that much a grasp on anything - but:
While NICE has a duty publish and promote its Guidelines it has no authority to make anyone take notice. It is a mistake to believe that the either the NHS or the Public Health services in the UK are constructed in any sort of joined up way, or that Government does not exploit this lack of cohesion for political purposes e.g deflecting responsibility, hiding funding deficiencies etc. NICE sits in its world and the various bits of the NHS sit in theirs with NHS Scotland being wholly divorced from NICE.
Of the bits of the NHS and NHS/Government interfaces (it's complicated, hence jargon word) that have a duty to apprise themselves of NICE Guidelines, those who Commission Services ( a mixed bag of CCGs etc) have to take note of services that are to be met in line with a given Guideline, however that is a different obligation to actually funding provision. Which is why we've had services that more or less comply with the 2007 CFS/ME Guideline, but provision is only sparsely available and often limited to only local or regional populations, the CCGs etc being obliged to commission services that comply with the Guideline, but not obliged to commission those services per se. If your head is hurting at this point - that is normal.
There are legal arguments to be made about CCG obligation to provide services but where funding is limited and competing demand is ubiquitous the Commissioners have wide discretion.
In addition to Commissioners, all clinicians have a duty to understand the Guidelines - this is relatively easy for specialists who only have to concern themselves with the Guideline or Guidelines that apply to their area of practice. For General Medicine things become more challenging - the sheer volume of material that a clinician has to stay up to date with is overwhelming, for hospital based GM this is to an extent made manageable by having multiple staff sharing knowledge and expertise. But profound difficulties arise for GPs, there is simply no way for every GP to stay on top of every development plus the avalanche of bureaucracy that the NHS generates for Primary Care.
GP per capita numbers in the UK have fallen in recent years and in 2018 the number was the same as it was in 2003 [1], although Scotland and NI have bucked this trend, the position in England is dire down to just 9 GPs per 20,000 patients [2]. Demand on GP time has increased largely because of the rapid rise in age related health care demand, while other structural changes such as the entry of large private sector operators into Primary Care (weird aspect of the NHS, GPs were always private contractors to the NHS but operated mainly as small partnerships) have impacted negatively how GPs interact with patients.
In the case of ME/CFS the patient to GP ratio is (using a patient population of 250k) just 6:1 (8 in England) i.e on overage each full time GP will have just 6 ME patients on their lists who they may not see from one year to the next. In comparison each GP would have a notional 1700 (2,200 England) people on their books. Many GPs may never see an ME/CFS patient and the reality is that most GPs are only going to look at the new Guideline when they have contact with a patient. And even then only if there's some requirement to do something different because of a change in the patient's health.
If there is no Commissioned service for the GP to refer the ME/CFS patient to, as is the case in most of the UK, then the Guideline is unlikely to have much impact for most patients. It's a moral victory - with practical gains (hopefully) further down the line.
[1]
https://www.nuffieldtrust.org.uk/ne...cross-the-uk#the-headline-trend-in-gp-numbers
[2]
https://www.bma.org.uk/advice-and-s...force/pressures/pressures-in-general-practice