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 NHS in England and Wales that:
offers best clinical advice for PD
is based on best published evidence and expert consensus
takes into account patient choice and informed decision making
defines the major components of NHS care provision for PD
indicates areas suitable for clinical audit
details areas of uncertainty or controversy requiring further research
provides a choice of guideline versions for different audiences.
2.2. Scope
The guideline was developed in accordance with a scope, which detailed the remit of the guideline originating from the Department of Health and specified those aspects of PD to be included and excluded.
Prior to the commencement of the guideline development, the scope was subjected to stakeholder consultation in accordance with processes established by NICE.1,13 The full scope is shown in Appendix A.
The guideline covers:
The scope excludes:
juvenile onset PD (in people younger than 20 years of age)
treatment of parkinsonism (a neurological disorder that manifests with hypokinesia, tremor or muscular rigidity) and other tremulous disorders (for example, essential tremor).
The guideline is relevant to primary, secondary and tertiary NHS care settings.
2.3. Audience
The guideline is primarily intended to provide guidance for NHS staff, but will also have relevance to the following people or organisations:
all healthcare professionals
people with the disease and carers of these people
patient support groups
commissioning organisations
service providers.
2.4. Involvement of people with Parkinson’s disease
The NCC-CC was keen to ensure that the views and preferences of people with PD and their carers informed all stages of the guideline. This was achieved:
by consulting the Patient Information Unit housed within NICE during the pre-development (scoping) and final validation stages of the guideline
by having a person with PD and a user organisation representative on the Guideline Development Group (GDG).
The patient and/or a representative of the user organisation were present at every meeting of the GDG. They were involved at all stages of the guideline development process and were able to consult with their wider constituencies.
2.5. Guideline limitations
The limitations of the guideline are as follows:
Clinical guidelines usually do not cover issues of service delivery, organisation or provision (unless specified in the remit from the Department of Health).
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.
2.6. Other work relevant to the guideline
This guideline has been developed with the knowledge that other national work on PD and chronic neurological conditions has been completed or is in progress. This includes:
the National Service Framework (NSF) for Long-term (Neurological) Conditions
14the NSF for Older People
15NICE Guideline on Falls
16NICE Guideline on Dementia
17NICE Guideline on Depression
18NICE Guideline on Epilepsy
19NICE Guidance on Alzheimer’s Disease
20NICE Guideline on Anxiety
21NICE Guideline on Nutrition
22NICE Guidance on Deep Brain Stimulation
23
2.7. The process of guideline development
The development of this evidence-based clinical guideline draws upon the methods described by the NICE Guideline Development Methods manual1,13 and the methodology pack specifically developed by the NCC-CC for each chronic condition guideline.24 The developers’ role and remit is summarised in .
Role and remit of the developers.
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 economics advice
distilling and synthesising the evidence and writing recommendations
grading the evidence statements and recommendations
agreeing the recommendations
structuring and writing the guideline
updating the guideline.
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 B.
Searching for the evidence
The information scientist developed a search strategy for each clinical question. In addition, the health economist searched for supplemental papers to inform models. Key words for the search were identified by the GDG. 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 all 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 were generated for each question together with the rationale for the exclusion. The exclusion lists were presented to the GDG. Full papers were obtained where relevant. Literature search details are shown in Appendix B.
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
Guideline development methods – information for National Collaborating Centres and guideline developers’ manual
1
Incorporating health economics advice
Due to the appointment of the health economist midway through the guideline development, the areas for health economic evidence were considered after the formation of the clinical questions. The health economist reviewed the clinical questions to consider the potential application of health economic evidence. Five key areas were separately identified by the clinical lead.
After agreement and selection of specific areas, the information scientist performed a literature search using economic filters on the related clinical questions. No study design criteria were imposed a priori. The searches were not limited to randomised controlled trials (RCTs) or formal economic evaluations. See the earlier section on ‘Searching for the evidence’ for details of the systematic search by the information scientist. The health economist reviewed titles and abstracts identified in the economic searches, and full papers were obtained as appropriate. The health economist critically appraised the full papers and the relevant data were presented to the GDG at subsequent GDG meetings. See the previous section for information on critically appraising the evidence.
The health economist performed supplemental literature searches using key search terms in the York Centre for Review and Dissemination database, the NHS Economic Evaluation database, PubMed and the Google search engine to obtain additional information for modelling. Areas were modelled due to the limited amount of evidence in or relevance to the UK setting. Assumptions and designs of the models were explained and agreed by the GDG members during meetings and validated by an additional health economist.
Distilling and synthesising the evidence and writing 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.
Evidence tables are available at: www.rcplondon.ac.uk/pubs/online_home.htm
Agreeing the recommendations
The sign-off workshop 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 sign-off workshop also reached agreement on the following:
In prioritising key recommendations for implementation, the sign-off workshop also 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.
The audit criteria provide suggestions of areas for audit in line with the key recommendations for implementation.2
Structuring and writing the guideline
The guideline is divided into sections for ease of reading. For each section the layout is similar and is described below.
Table 2.2Grading the evidence statements and recommendations
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| Levels of evidence | | Classification of recommendations |
|---|
| Level | Type of evidence | Class | Evidence |
|---|
| 1++ | High-quality meta-analysis (MA), systematic reviews (SR) of randomised controlled trials (RCTs), or RCTs with a very low risk of bias | A | Level 1++ and directly applicable to the target population
or
Level 1+ and directly applicable to the target population AND consistency of results
Evidence from NICE technology appraisal |
| 1+ | Well-conducted MA, SR or RCTs, or RCTs with a low risk of bias |
| 1− | MA, SR of RCTs, or RCTs with a high risk of bias | Not used as a basis for making a recommendation |
| 2++ | High-quality SR 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 | B | Level 2++, directly applicable to the target population and demonstrating overall consistency of results
or
Extrapolated evidence from 1++ or 1+ |
| 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 | Not used as a basis for making a recommendation |
| 3 | Non-analytic studies (for example case reports, case series) | C | Level 2+, directly applicable to the target population and demonstrating overall consistency of results
or
Extrapolated evidence from 2++ |
| 4 | Expert opinion, formal consensus | D | Level 3 or 4
or
Extrapolated from 2+
or
Formal consensus |
| D (GPP) | A good practice point (GPP) is a recommendation based on the experience of the GDG |
Diagnostic study level of evidence and classification of recommendation was also included.1
Clinical introduction: sets a succinct background and describes the clinical context.
Methodological introduction: describes any issues or limitations that were apparent when reading the evidence base.
Evidence statements: provide a synthesis of the evidence base and usually describe what the evidence showed in relation to the outcomes of interest.
Health economics: presents, where appropriate, an overview of the cost-effectiveness evidence-base.
From evidence to recommendation: sets out the GDG decision-making rationale and provides a clear and explicit audit trail from the evidence to the evolution of the recommendations.
Recommendations: provides stand-alone, action-oriented recommendations.
Evidence tables
The evidence tables are not published as part of the full guideline but are available on-line at www.rcplondon.ac.uk/pubs/books/pd. These describe comprehensive details of the primary evidence that was considered during the writing of each section.
Writing the guideline
The first draft version of the guideline was drawn up by the Technical Team in accord with the decision of the GDG. The guideline was then submitted for two formal rounds of public and stakeholder consultation prior to publication.1,13 The registered stakeholders for this guideline are detailed in Appendix I. 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 February 2005 to be considered. Future guideline updates will consider evidence published after this cut-off date.
Two years after publication of the guideline, NICE will commission 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 updated approximately 4 years after publication.1,13
2.8. 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.
2.9. Funding
The National Collaborating Centre for Chronic Conditions was commissioned by the National Institute for Health and Clinical Excellence to undertake the work on this guideline.
