2.1. Aim
The aim of the National Collaborating Centre for Chronic Conditions (NCC-CC) is to provide a user-friendly, clinical, evidence-based guideline for the National Health Service (NHS) in England and Wales that:
offers best clinical advice for the diagnosis and acute management of stroke and TIA
is based on best published clinical and economic evidence, alongside expert consensus
takes into account patient choice and informed decision-making
defines the major components of NHS care provision for the management of acute stroke and TIA
details areas of uncertainty or controversy requiring further research
provides a choice of guideline versions for differing audiences.
2.2. Scope
The guideline was developed in accordance with a scope, which detailed the remit of the guideline originating from the DH and specified the aspects of diagnosis and the management of acute stroke and TIA care to be included and excluded.
Prior to guideline development, the scope was subjected to stakeholder consultation in accordance with processes established by National Institute for Health and Clinical Excellence (NICE).1 The full scope is shown in Appendix B, available online at www.rcplondon.ac.uk/pubs/brochure.aspx?e=250
2.3. Audience
The guideline is intended for use by the following people or organisations:
all healthcare professionals
people with acute stroke or TIA and their carers
patient support groups
commissioning organisations
service providers.
2.4. Involvement of people with stroke and TIA
The NCC-CC was keen to ensure the views and preferences of people with stroke and TIA and their carers were informed at all stages of the guideline. This was achieved by:
having two people with experience of stroke and TIA as patient representatives on the guideline development group
consulting the Patient and Public Involvement Programme (PPIP) housed within NICE during the pre-development (scoping) and final validation stages of the guideline project
the inclusion of patient groups as registered stakeholders for the guideline.
2.5. Guideline limitations
These include:
NICE clinical guidelines usually do not cover issues of service delivery, organisation or provision (unless specified in the remit from the DH).
NICE is primarily concerned with health services and so recommendations are not provided for social services and the voluntary sector. However, the guideline may address important issues in how NHS clinicians interface with these other sectors.
Generally, the guideline does not cover rare, complex, complicated or unusual conditions.
Where a meta-analysis was available, generally the individual papers contained within were not appraised.
It is not possible in the development of a clinical guideline to complete extensive systematic literature review of all pharmacological toxicity. NICE advises that the guidelines are read alongside the summaries of product characteristics (SPCs).
Overall, the evidence review identified very few randomised controlled trials (RCTs) or high-quality case-control or cohort studies. Many of the studies had a small sample size and were consequently statistically under-powered. Also, some studies relied on retrospective data collection or post-hoc analysis. Furthermore, the different diagnostic tests, interventions and outcomes often precluded any meaningful comparison across studies.
2.6. Other work relevant to the guideline
Related NICE guidance:
‘Alteplase for the treatment of acute ischaemic stroke’,
NICE technology appraisal no. TA122 (2007). Available from
www.nice.org.uk/TA122‘Vascular disease – clopidogrel and dipyridamole’,
NICE technology appraisal no. TA90 (2005). Available from
www.nice.org.uk/TA90‘Nutrition support in adults: oral nutrition support, enteral tube feeding and parenteral nutrition’,
NICE clinical guideline CG32 (2006). Available from
www.nice.org.uk/CG32‘Hypertension: management of hypertension in adults in primary care’,
NICE clinical guideline CG34 (2006). Available from
www.nice.org.uk/CG34‘Diagnosis and management of Type 1 diabetes in children, young people and adults’,
NICE clinical guideline CG15 (2004). Available from
www.nice.org.uk/CG15‘Lipid modification guideline’,
NICE clinical guideline CG67 (2008). Available from
www.nice.org.uk/CG67
2.7. Methodological background
The development of this evidence-based clinical guideline draws upon the methods described by the NICE’s ‘Guideline development methods manual’1 and the methodology pack8 specifically developed by the NCC-CC for each chronic condition guideline. The developers’ role and remit is summarised in below.
Role and remit of the developers.
2.8. The process of guideline development
The basic steps in the process of producing a guideline are:
developing clinical evidence-based questions
systematically searching for the evidence
critically appraising the evidence
incorporating health economic evidence
distilling and synthesising the evidence and writing recommendations
grading the evidence statements
agreeing the recommendations
structuring and writing the guideline
updating the guideline.
1. Developing evidence-based questions
The technical team drafted a series of clinical questions that covered the guideline scope. The GDG and Project Executive refined and approved these questions, which are shown in Appendix A, available online at www.rcplondon.ac.uk/pubs/brochure.aspx?e=250
2. Searching for the evidence
The information scientist developed a search strategy for each question. Key words for the search were identified by the GDG. In addition, the health economist searched for additional papers providing economic evidence or to inform detailed health economic work (for example, modelling). Papers that were published or accepted for publication in peer-reviewed journals were considered as evidence by the GDG. Conference paper abstracts and non-English language papers were excluded from the searches.
Each clinical question dictated the appropriate study design that was prioritised in the search strategy but the strategy was not limited solely to these study types. The research fellow or health economist identified titles and abstracts from the search results that appeared to be relevant to the question. Exclusion lists, generated for each question together with the rationale for the exclusion, were presented to the GDG. Full papers were obtained where relevant. See Appendix A, available online at www.rcplondon.ac.uk/pubs/brochure.aspx?e=250 for literature search details.
3. Appraising the evidence
The research fellow or health economist, as appropriate, critically appraised the full papers. In general, no formal contact was made with authors. However, there were ad hoc occasions when this was required in order to clarify specific details. Critical appraisal checklists were compiled for each full paper. One research fellow undertook the critical appraisal and data extraction. The evidence was considered carefully by the GDG for accuracy and completeness.
All procedures are fully compliant with the:
NICE methodology as detailed in the ‘Guideline development methods – information for national collaborating centres and guideline developers’ manual’ 2007.
1
4. Health economic evidence
Areas for health economic modelling were agreed by the GDG after the formation of the clinical questions. The health economist reviewed the clinical questions to consider the potential application of health economic modelling, and these priorities were agreed with the GDG.
The health economist performed supplemental literature searches to obtain additional data for modelling. Assumptions and designs of the models were explained to and agreed by the GDG members during meetings, and they commented on subsequent revisions.
5. Distilling and synthesising the evidence and developing recommendations
The evidence from each full paper was distilled into an evidence table and synthesised into evidence statements before being presented to the GDG. This evidence was then reviewed by the GDG and used as a basis upon which to formulate recommendations. The criteria for grading evidence are shown in .
Evidence tables are available online at www.rcplondon.ac.uk/pubs/brochure.aspx?e=250
6. Grading the evidence statements
Table 2.2Grading the evidence statements NICE 20071
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| Level of evidence | Type of evidence |
|---|
| 1++ | High-quality meta-analyses, systematic reviews of RCTs, or RCTs with a very low risk of bias. |
| 1+ | Well-conducted meta-analyses, systematic reviews of RCTs, or RCTs with a low risk of bias. |
| 1− | Meta-analyses, systematic reviews of RCTs, or RCTs with a high risk of bias.* |
| 2++ | High-quality systematic reviews of case-control or cohort studies.
High-quality case-control or cohort studies with a very low risk of confounding, bias or chance and a high probability that the relationship is causal. |
| 2+ | Well-conducted case-control or cohort studies with a low risk of confounding, bias or chance and a moderate probability that the relationship is causal. |
| 2− | Case-control or cohort studies with a high risk of confounding, bias or chance and a significant risk that the relationship is not causal.* |
| 3 | Non-analytic studies (for example case reports, case series). |
| 4 | Expert opinion, formal consensus. |
- *
Studies with a level of evidence ‘–’ are not used as a basis for making a recommendation.
RCT, randomised controlled trial
7. Agreeing the recommendations
The GDG employed formal consensus techniques to:
ensure that the recommendations reflected the evidence base
approve recommendations based on lesser evidence or extrapolations from other situations
reach consensus recommendations where the evidence was inadequate
debate areas of disagreement and finalise recommendations.
The GDG also reached agreement on the following:
In prioritising key recommendations for implementation, the GDG took into account the following criteria:
high clinical impact
high impact on reducing variation
more efficient use of NHS resources
allowing the patient to reach critical points in the care pathway more quickly.
Audit criteria for this guideline will be produced by NICE, following publication, in order to provide suggestions of areas for audit in line with the key recommendations for implementation.
8. Structuring and writing the guideline
The guideline is divided into sections for ease of reading. For each section, the layout is similar and contains:
Clinical introduction sets a succinct background and describes the current clinical context.
Methodological introduction describes any issues or limitations that were apparent when reading the evidence base. Point estimates (PE) and confidence intervals (CI) are provided for all outcomes in the evidence tables, available online at
www.rcplondon.ac.uk/pubs/brochure.aspx?e=250. In addition, within the guideline PE and CI are cited in summary tables. In the absence of a summary table, PE and CI should be provided in the narrative text when the outcome adds something to the text and to make a particular point. These may be primary or secondary outcomes that were of particular importance to the GDG when discussing the recommendations. The rationale for not citing
all statistical outcomes in the text is to try to provide a ‘user friendly’ readable guideline balanced with statistical evidence where this is thought to be of interest to the reader.
Evidence statements provides a synthesis of the evidence base and usually describes what the evidence showed in relation to the outcomes of interest.
Health economics presents, where appropriate, an overview of the cost effectiveness of evidence base, or any economic modelling.
From evidence to recommendations this section sets out the GDG decision-making rationale, providing a clear and explicit audit trail from the evidence to the evolution of the recommendations.
Recommendations provides stand alone, action-orientated recommendations.
Evidence tables the evidence tables are not published as part of the full guideline but are made publicly available online at
www.rcplondon.ac.uk/pubs/brochure.aspx?e=250. These describe comprehensive details of the primary evidence that was considered during the writing of each section including all statistical outcomes.
9. Writing the guideline
The first draft version of the guideline was drawn up by the technical team in accord with the decisions of the GDG, incorporating contributions from individual GDG members in their expert areas and edited for consistency of style and terminology. The guideline was then submitted for a formal public and stakeholder consultation prior to publication. The registered stakeholders for this guideline are detailed on the NICE website, www.nice.org.uk. Editorial responsibility for the full guideline rests with the GDG.
Updating the guideline
Literature searches were repeated for all of the evidence-based questions at the end of the GDG development process allowing any relevant papers published up until 31 October 2007 to be considered. Future guideline updates will consider evidence published after this cut-off date.
Two years after publication of the guideline, NICE will ask a National Collaborating Centre to determine whether the evidence base has progressed significantly to alter the guideline recommendations and warrant an early update. If not, the guideline will be considered for update approximately four years after publication.
2.9. Disclaimer
Healthcare providers need to use clinical judgement, knowledge and expertise when deciding whether it is appropriate to apply guidelines. The recommendations cited here are a guide and may not be appropriate for use in all situations. The decision to adopt any of the recommendations cited here must be made by the practitioner in light of individual patient circumstances, the wishes of the patient, clinical expertise and resources.
The NCC-CC disclaims any responsibility for damages arising out of the use or non-use of these guidelines and the literature used in support of these guidelines.
2.10. Funding
The NCC-CC was commissioned by the NICE to undertake the work on this guideline.
