3.1.1. Literature search strategy

The aim of the literature review was to identify and synthesise relevant published evidence to answer specific clinical questions formulated and agreed by the guideline development group. Searches were performed using generic and specially developed filters, relevant medical subject heading terms and free-text terms. Details of all literature searches are available from the NCC-WCH.

Searches were carried out for each topic of interest. The Cochrane Library (up to Issue 4, 2003) was searched to identify systematic reviews (with or without meta-analyses) of randomised controlled trials (RCTs) as well as individual RCTs. The electronic databases MEDLINE (Ovid version for the period January 1966 to December 2003), EMBASE (Ovid version for the period January 1980 to December 2003), the Cumulative Index to Nursing and Allied Health Literature (Ovid version for the period January 1982 to December 2003), PsycINFO (Ovid version for the period January 1974 to December 2003), and the Database of Abstracts of Reviews of Effects were also searched.

There was no systematic attempt to search the ‘grey literature’ (conferences, abstracts, theses and unpublished trials).

The National Guidelines Clearinghouse database, the Turning Research into Practice database and the Organising Medical Networked Information service on the Internet were searched for guidelines produced by other development groups. The reference lists in these guidelines were checked against our searches to identify any missing evidence.

A preliminary scrutiny of titles and abstracts was undertaken and full copies of all publications that addressed the guideline development group's clinical questions were obtained. Following a critical appraisal of each publication, studies not relevant to a particular clinical question were excluded. Studies that did not report relevant outcomes were also excluded. Evidence submitted by stakeholder organisations that was relevant to the guideline development group's clinical questions and was of equivalent or better quality than evidence identified in the literature searches was also included.

It was thought that there would not be a large body of economic evidence and that specific searches could miss some relevant studies. A general search was therefore designed to find all economic studies relating to children and young people with type 1 diabetes. Additional search terms relating to economic studies were added to a search string for identifying the clinical effectiveness evidence on children and young people with type 1 diabetes. A second search on topics relating to education and psychological interventions was also undertaken. The searches were undertaken using the same databases as the clinical effectiveness searches. Additional searches were undertaken of the Health Economic Evaluations Database and the National Health Service Economic Evaluations Database.

Abstracts and/or database reviews of papers that were identified by the economic searches were reviewed and excluded if they contained no economic data or if the focus of the paper explicitly excluded children and young people. Relevant references in the bibliographies of reviewed papers were also identified and reviewed.

3.1.2. Synthesis of clinical effectiveness evidence

Evidence relating to clinical effectiveness was reviewed using established guides^3–9 and classified using the established hierarchical system shown in Table 6. This system reflects the susceptibility to bias that is inherent in particular study designs

Table 6

Levels of evidence.

The type of clinical question dictates the highest level of evidence that may be sought. For issues of therapy or treatment, the highest possible level of evidence is a systematic review or meta-analysis of RCTs (evidence level Ia) or an individual RCT (evidence level Ib). For issues of prognosis, the highest possible level of evidence is a cohort study (evidence level IIb).

For each clinical question, the highest available level of evidence was selected. Where appropriate, for example, if a systematic review, meta-analysis or RCT existed in relation to a question, studies of a weaker design were ignored. Where systematic reviews, meta-analyses and RCTs did not exist, other appropriate experimental or observational studies were sought. For diagnostic tests, test evaluation studies examining the performance of the test were used if the efficacy of the test was required, but where an evaluation of the effectiveness of the test in the clinical management of patients and the outcome of disease was required, evidence from RCTs or cohort studies was used.

Evidence was synthesised qualitatively by summarising the content of identified papers in evidence tables and agreeing brief statements that accurately reflected the evidence. Quantitative synthesis (meta-analysis) was performed where appropriate.

Summary results and data are presented in the guideline text. More detailed results and data are presented in the accompanying evidence tables. Where possible, dichotomous outcomes are presented as relative risks (RRs) with 95% confidence intervals (CIs), and continuous outcomes are presented as mean differences with 95% CIs or standard deviations (SDs) or standard errors (SEs) where CIs were not reported. Statistically significant RRs are also presented as numbers needed to treat (NNTs) where appropriate. Meta-analyses based on dichotomous outcomes are presented as pooled RRs with 95% CIs, and meta-analyses based on continuous outcomes are presented as weighted mean differences (WMDs) with 95% CIs. The results of meta-analyses that were performed specifically for this guideline are also presented as forest plots in Appendix J:.

3.1.3. Health economics

The purpose of the economic input to the guideline was to inform the guideline development group of potential economic issues that needed to be considered, to review the economic literature, and to carry out economic analyses agreed with the guideline development group where appropriate data were available.

Since the overall body of literature was expected to be small, the economic review considered all types of economic studies (cost benefit, cost effectiveness, cost utility, cost consequence and cost minimisation). The cost data were only considered if they were generalisable to England and Wales, or if resource use was described in sufficient detail to be able to apply UK cost data.

It was agreed that economic models using data from the clinical literature review should be considered where guideline recommendations had major resource implications, or represented a change in policy, or where clinical effectiveness data from well conducted studies were available.

3.1.4. Young people's consultation day

A young people's consultation day was organised for this guideline in collaboration with the National Children's Bureau (NCB). The objective of the consultation day was to elicit the views of young people with type 1 diabetes and their carers in relation to topics considered in the guideline. A summary of the conclusions reached following the consultation day is presented in Appendix M:. Issues relating to specific topics are also discussed in relevant sections of the guideline.

3.1.5. Forming and grading recommendations

For each clinical question, recommendations were derived using, and explicitly linked to, the evidence that supported them. Where possible, the guideline development group worked on an informal consensus basis. Where necessary, formal consensus methods (such as modified Delphi and nominal group techniques) were used to agree recommendations and audit criteria.

Each recommendation was graded according to the level of evidence upon which it was based using the established system shown in Table 7. For issues of therapy or treatment, the best possible level of evidence (a systematic review or meta-analysis or an individual RCT) would equate to a grade A recommendation. For issues of prognosis, the best possible level of evidence (a cohort study) would equate to a grade B recommendation. However, this should not be interpreted as an inferior grade of recommendation because it represents the highest level of relevant evidence.

Table 7

Grading of recommendations.

3.1.6. External review

The guideline has been developed in accordance with the NICE guideline development process. This has included giving registered stakeholders the opportunity to comment on the scope of the guideline, the first draft of the full and summary guidelines and the second drafts of the full and summary guidelines. In addition the first and second drafts were reviewed by an independent Guideline Review Panel (GRP) established by NICE.

The comments made by the stakeholders and the GRP were collated and presented anonymously for consideration by the guideline development group. All comments were considered systematically by the guideline development group and the resulting actions and responses were recorded.

3.1.7. Outcome measures used in the guideline

For this guideline, the management of type 1 diabetes has been assessed against a number of outcome measures linked to physical and behavioural responses to care. Some of the outcome measures relate to responses that are regarded as beneficial (such as maintenance of glycaemic control), while others relate to responses that are regarded as undesirable (such as episodes of severe hypoglycaemia and diabetic ketoacidosis). Priority outcome measures, which were agreed by the guideline development group on the basis of their relevance to patients and professionals, are shown in Table 8.

Table 8

Priority outcome measures.

3.1.8. Terminology used in the guideline

The internationally agreed term ‘type 1 diabetes’¹¹ is used in this guideline, rather than ‘insulin-dependent diabetes mellitus’. Similarly, ‘type 2 diabetes’ is used in the guideline, rather than ‘non-insulin-dependent diabetes mellitus’.

The guideline relates to the care of children (people younger than 11 years) and young people (those aged 11 years or over, but under 18 years). Where appropriate, the following terms are used to refer to specific age groups:

• neonates (0 weeks or older and younger than 4 weeks)
• infants (4 weeks or older and younger than 52 weeks)
• pre-school children (1 year or older and younger than 5 years)
• primary school children (5 years or older and younger than 11 years)
• young people (11 years or older and younger than 18 years)
• adults (18 years or older).

Where children are too young to make informed decisions, their treatment and care should be discussed in consultation with their parents (or legal guardians). Some aspects of care will also require discussion with, or provision of information for, other family members (such as siblings) and carers who are not part of the family (for example, childminders and school staff).

3.2.1. Introduction

This guideline was commissioned by NICE and developed in accordance with the process outlined in the 2009 and 2012 editions of The guidelines manual. Table 9 summarises the key stages of the process and which version was followed for each stage.

Table 9

Stages in the NICE guideline development process and versions of The guidelines manual followed at each stage.

Information about the clinical areas covered by the guideline (and those that are excluded) is available in the scope of the guideline (reproduced in Appendix B:). A list of registered stakeholder organisations is presented in Appendix C:.

All guideline development group members' potential and actual conflicts of interest were recorded on declaration forms provided by NICE (summarised in Appendix D:). (The guideline development group chair and members, and the expert advisers to the group, were recruited under NICE's April 2007 code of conduct on declaring and dealing with conflicts of interest.) The Chair of the diabetic ketoacidosis (DKA) subgroup was an author of some studies considered by the group, and so group discussions that included consideration of such studies were chaired by the NCC-WCH's clinical director. These occasions are documented in relevant sections of the guideline. No other interests declared by guideline development group members constituted a material conflict of interest that would influence recommendations developed by the group.

Organisations with an interest in the diagnosis and management of diabetes in children and young people were encouraged to register as stakeholders for the guideline. Registered stakeholders were consulted throughout the guideline development process.

In accordance with NICE's equality scheme, ethnic and cultural considerations and factors relating to disabilities were considered by the guideline development group throughout the development process and specifically addressed in individual recommendations where relevant. Further information is available from: www.nice.org.uk/About/Who-we-are/Policies-and-procedures/NICE-equality-scheme

This is one of 5 NICE clinical guidelines that were developed in the same timescale to address diabetes care:

• Diabetes (type 1 and type 2) in children and young people this guideline, which was developed by the National Collaborating Centre for Women's and Children's Health [NCC-WCH])
• Diabetes in pregnancy (developed by the NCC-WCH)
• Type 1 diabetes in adults (developed by the National Clinical Guideline Centre [NCGC])
• Type 2 diabetes in adults (developed by the Internal Clinical Guidelines Programme, Centre for Clinical Practice, NICE)
• Diabetic foot problems (developed by the Internal Clinical Guidelines Programme, Centre for Clinical Practice, NICE).

NICE set up a steering committee to oversee the production of the 5 clinical guidelines. The group, which included the chairs of the guideline development groups, together with staff from the 3 guidance-producing centres and NICE, identified and resolved gaps and overlaps across the different guidance topics to ensure that the final guidelines were complementary and consistent. The guidance-producing centres shared systematic reviews and draft guideline outputs to facilitate this.

3.2.2. Developing review questions and protocols and identifying evidence

The guideline development group for this guideline formulated review questions based on the scope (see Appendix B:) and prepared a protocol for each review question (see Appendix E:). These formed the starting point for systematic reviews of relevant evidence. Published evidence was identified by applying systematic search strategies (see Appendix F:) to the following databases: Medline (1946 onwards), Embase (1974 onwards), the Health Technology Assessment (HTA) database and 3 Cochrane databases (Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and the Database of Abstracts of Reviews of Effects). Searches to identify economic studies were undertaken using the above databases and the NHS Economic Evaluation Database (NHS EED). The Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1980 onwards) and PsycINFO (1806 onwards) were searched for selected topics only (these were review questions related to dietary advice and those related to psychological and/or behavioural interventions). Where possible, searches were limited to English-language only. Generic and specially developed search filters were used to identify particular study designs, such as RCTs. There was no systematic attempt to search grey literature (conference abstracts, theses or unpublished trials), nor was hand searching of journals not indexed on the databases undertaken.

Towards the end of the guideline development process, the searches were updated and re-executed to include evidence published and indexed in the databases by 26 August 2014.

3.2.3. Reviewing and synthesising evidence

The number of studies identified for each review question is summarised in Appendix G: Some studies were excluded from the guideline reviews because they did not meet inclusion criteria specified by the guideline development group (see Appendix H:). The characteristics of each included study were summarised in evidence tables for each review question (see Appendix I:).

Raw data, or odds ratios (ORs), relative risks (RRs) or hazard ratios, together with their 95% confidence intervals (CIs), from multivariate analyses were extracted from the articles where appropriate. Data for the outcomes defined in the review protocol are summarised in tables within the relevant evidence review. Full data for all the outcomes are presented in the evidence tables (see Appendix I:).

Evidence related to clinical effectiveness was synthesised and evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Using this approach, the quality of the evidence identified for each outcome listed in the review protocol is assessed according to the factors listed below and an overall quality rating (very low, low, moderate or high) is assigned by combining the ratings for the individual factors.

• study design (as an indicator of intrinsic bias; this determines the initial quality rating)
• limitations in the design or execution of the study (including concealment of allocation, blinding, loss to follow-up; these can reduce the quality rating)
• inconsistency of effects across studies (this can reduce the quality rating)
• indirectness (the extent to which the available evidence fails to address the specific review question; this can reduce the quality rating)
• imprecision (this can reduce the quality rating)
• other considerations (including large magnitude of effect, evidence of a dose-response relationship, or confounding variables likely to have reduced the magnitude of an effect; these can increase the quality rating in observational studies provided no downgrading for other features has occurred).

GRADE findings are presented in full in Appendix K:, with abbreviated versions (summaries of findings without the individual components of the quality assessment) presented in this document.

The type of review question determines the highest level of evidence that may be sought to answer a question. For issues of therapy or treatment, this is a well conducted systematic review or meta-analysis of RCTs or an individual RCT. Where systematic reviews, meta-analyses or individual RCTs were not identified, other appropriate experimental or observational studies were sought.

For diagnostic questions, studies evaluating the performance of the test were sought, and sensitivity, specificity and likelihood ratios for positive and negative test results (LR+ and LR−, respectively) were calculated or quoted where possible (see Table 10). Where an evaluation of the effectiveness of the test in the clinical management of the condition was required, evidence from RCTs or cohort studies was considered optimal. NICE recommends using the Quality Assessment of Studies of Diagnostic Accuracy (QUADAS) methodology checklist to assess the quality of diagnostic studies (see the NICE guidelines manual).

Table 10

‘2×2’ table for calculation of diagnostic test accuracy parameters.

It is necessary to predetermine values for minimally important differences (MIDs) for outcomes in order to make an assessment of imprecision. The MIDs were discussed and agreed with the guideline development group before the reviews commenced. For dichotomous outcomes the defaults of ±0.25 for RRs and ORs relative to no effect (RR=1 or OR=1) were used and imprecision was graded according to the following 3 ‘zones’ for effect estimates: less than 0.75; 0.75 to 1.25; greater than 1.25. If the CI for a particular effect estimate was wholly within 1 of the zones then the outcome would be graded as having no serious imprecision; if the CI spanned 2 of the zones, the outcome would be graded as having ‘serious imprecision’; and if the CI spanned all 3 zones, then the outcome would be graded as having ‘very serious imprecision’.

Where outcomes were continuous variables the MID was agreed at the protocol stage with the guideline development group and used when judging whether observed differences between treatment groups were considered clinically important (see Section 3.2.7 for details of MIDs used in this guideline). As with dichotomous outcomes, zones for determining imprecision of effect estimates were defined and applied based on the value that would correspond to no effect (for example a mean difference of zero) and then added to or subtracted from the MID.

The body of evidence identified for each review question (or part of a review question) was presented in a GRADE evidence profile which summarised the quality of the evidence by outcome and the findings (pooled relative and absolute effect sizes, and associated CIs). Where possible, the body of evidence corresponding to each outcome specified in the review protocol was subjected to quantitative meta-analysis. In such cases, pooled effect sizes were presented as pooled RRs, pooled ORs or weighted mean differences (WMDs). By default, meta-analyses were conducted by fitting fixed effect models, but where statistically significant heterogeneity was identified random effects models were used. Where quantitative meta-analysis could not be undertaken (for example because of heterogeneity in the included studies) the effect sizes reported in the included studies were presented for each individual study. Forest plots for meta-analyses conducted for the guideline are presented in Appendix J:.

3.2.4. Assessing cost effectiveness

The aims of the health economic input to the guideline were to inform the guideline development group of potential economic issues related to diagnosis and management of type 1 and type 2 diabetes in children and young people, and to ensure that recommendations represented a cost-effective use of healthcare resources. Health economic evaluations aim to integrate data on benefits (ideally in terms of quality adjusted life years [QALYs]), harms and costs of different care options.

The guideline development group prioritised a number of review questions where it was thought that economic considerations would be particularly important in formulating recommendations. A single global systematic search for published economic evidence was undertaken to cover all clinical topics addressed in the guideline. For economic evaluations, no standard system of grading the quality of evidence exists and included papers were assessed using a quality assessment checklist based on good practice in economic evaluation. Reviews of the relevant published health economic literature are presented in Section 20 and summarised alongside the relevant clinical effectiveness reviews.

Health economic considerations were aided by original economic analysis undertaken as part of the development process. For this guideline the areas prioritised for economic analysis were:

• effectiveness of structured education programmes for children and young people with type 1 diabetes (see Section 5.4 and Section 20.2)
• comparative effectiveness of multiple daily injections of insulin and mixed insulin injections in children and young people with type 1 diabetes (see Section 6.1.2 and Section 20.3)
• dietary advice based on carbohydrate counting in children and young people with type 1 diabetes using multiple daily injections of insulin (see Section 6.4.3)
• frequency of capillary blood glucose (finger-prick) testing in children and young people with type 1 diabetes (see Section 7.4.4 and Section 20.4)
• comparative effectiveness of capillary blood glucose testing and continuous glucose monitoring in children and young people with type 1 diabetes (see Section 7.5.10)
• comparative effectiveness of continuous glucose monitoring performed intermittently and continuous glucose monitoring performed in real-time in children and young people with type 1 diabetes (see Section 7.5.11)
• comparative effectiveness of blood ketone monitoring and urine ketone monitoring for the prevention of DKA (see Section 7.8 and Section 20.5).

Original analysis was not undertaken for all these areas. For structured education programmes there was recently published economic evidence undertaken from an NHS perspective (Christie 2014). For continuous glucose monitoring the guideline development group's view was that the clinical evidence was not sufficiently robust to support a recommendation for routine use and therefore the group felt that modelling was not needed to aid recommendations. The health economic analyses that were undertaken are described in detail in Section 20.

3.2.5. Evidence to recommendations

For each review question recommendations for clinical care were derived using, and linked explicitly to, the evidence that supported them. In the first instance, informal consensus methods were used by the guideline development group to agree short clinical and, where appropriate, cost effectiveness evidence statements which were presented alongside the evidence profiles. Statements summarising the group's interpretation of the evidence and any extrapolation from the evidence used to form recommendations were also prepared to ensure transparency in the decision-making process. The criteria used in moving from evidence to recommendations were:

• relative value placed on the outcomes considered
• consideration of the clinical benefits and harms
• consideration of net health benefits and resource use
• quality of the evidence
• other considerations (including equalities issues).

In areas where no substantial clinical research evidence was identified the guideline development group considered other evidence-based guidelines and consensus statements or used their collective experience to identify good practice. The health economics justification in areas of the guideline where the use of NHS resources (interventions) was considered was based on group consensus in relation to the likely cost effectiveness implications of the recommendations. The group also identified areas where evidence to answer their review questions was lacking and used this information to formulate recommendations for future research.

Towards the end of the guideline development process, formal consensus methods were used to consider all the clinical care recommendations and research recommendations that had been drafted previously, including those brought forward from the 2004 guideline. The guideline development group identified 10 key priorities for implementation (key recommendations) and 5 high-priority research recommendations. The key priorities for implementation were those recommendations thought likely to have the biggest impact on the care of children and young people with type 1 or type 2 diabetes in the NHS as a whole; these were selected using a variant of the nominal group technique (see the NICE guidelines manual). The priority research recommendations were selected in a similar way. Questions to be addressed through further research are listed in the relevant sections of the guideline. Further details, including a summary of why further research is important for topics covered by the scope of the 2015 update and summaries of changes made to research recommendations contained in the 2004 guideline, are presented in Appendix L:.

During the selection of key priorities for implementation and key recommendations all guideline development group members had an opportunity to nominate clinical recommendations and research recommendations as potential priorities. The interests declared by group members did not impact on the eventual selection of key priorities for implementation or key research recommendations because the only potential conflict of interest (due to the DKA sub-group chair's involvement in research related to when to start and stop intravenous insulin therapy for the management of DKA; see Section 18.4.4.1) was unrelated to any of the recommendations nominated as potential priorities.

3.2.6. Stakeholder involvement

Registered stakeholder organisations were invited to send representatives to a stakeholder scoping workshop and to comment on the draft scope and draft guideline for consultation. The guideline development group carefully considered and responded to all comments received from stakeholder organisations. The comments and responses were reviewed by NICE in accordance with the NICE guideline development process.

3.2.7. Specific considerations for this guideline

The guideline scope defines children and young people as those younger than 18 years. At the beginning of the development process the guideline development group agreed that for each review question the initial approach would be to include studies only if they reported results for people younger than 18 years. This approach was relaxed for a few review questions (for example intravenous osmotic agents for the management of cerebral oedema) where otherwise there would have been very little or no evidence for the group to consider (these exceptions are noted in the corresponding review protocols). Additionally, the NICE clinical guidelines addressing care for adults with type 1 or type 2 diabetes (Type 1 diabetes in adults and Type 2 diabetes in adults) were available where evidence specific to children and young people was lacking and extrapolation from adult evidence or recommendations was agreed by the guideline development group to be appropriate, although in most cases the group used informal consensus to formulate recommendations where evidence specific to children and young people was lacking.

Selected searches were date-limited to capture evidence published since the searches for the 2004 guideline were completed (December 2003). Where searches were date-limited this is indicated in the corresponding review protocol (see Appendix F:) and relevant studies considered in the 2004 guideline were retained and included in GRADE evidence profiles. Date-limited searches were limited to January 2003 onwards to ensure that relevant articles published in or after December 2003 were identified (because some databases do not allow date-limited searches to be specified by a particular month but only by a particular year).

The outcomes presented in GRADE profiles were identified as priorities by the guideline development group during review protocol development. For most review questions, the group limited the number of outcomes to 7 from the outset, and all of these were regarded as being critical to the formulation of recommendations. For a few questions where prioritisation of outcomes was more difficult, the group initially identified more than 7 outcomes with a view to extracting data for those most frequently reported in the studies identified for inclusion: for these questions the body of evidence identified for consideration was subsequently found to be sufficiently small for all outcomes reported in the included studies and listed in the review protocols to be extracted for consideration by the group.

For review questions in which the level of glycated haemoglobin (HbA1c) was prioritised as an outcome, evidence was extracted and presented in evidence tables and GRADE profiles using Diabetes Control and Complications Trial (DCCT) units (percentages) to allow inclusion of historical evidence. The guideline development group was, however, aware that current practice is to use International Federation of Clinical Chemistry (IFCC) units (mmol/mol) and these units were used when specific HbA1c levels were included in recommendations.

3.2.7.1. Minimally important differences

For dichotomous outcomes the defaults of ±0.25 for RRs and odds ratios ORs relative to no effect (RR=1 or OR=1) were used to assess imprecision.

MIDs for continuous variables were agreed by the guideline development group in advance of considering relevant evidence where possible, and agreed MIDs are reflected in footnotes to the GRADE profiles. MIDs that were used across several review questions are presented in Table 11.

Table 11

Minimally important differences for continuous variables used as outcomes across review questions.

For reviews of diagnostic or predictive accuracy of tests the following terms and thresholds were used to define the usefulness of the index test:

Sensitivity and specificity:

• low: 74.9% or below
• moderate: 75% to 89.9%
• high: 90% or above

Positive likelihood ratio:

• not useful: less than 5
• moderately useful: 5 or more but less than 10
• very useful: 10 or more

Negative likelihood ratio:

• not useful: more than 0.5
• moderately useful: more than 0.1 up to (and including) 0.5
• very useful: 0.1 or below

For correlation coefficients the following terms were used to indicate the strength of the correlation:

• very low or no correlation: r-value of 0 to 0.19 (or 0 to −0.19)
• low correlation: r-value of 0.2 to 0.39 (or −0.2 to −0.39)
• moderate correlation: r-value of 0.4 to 0.59 (or −0.4 to −0.59)
• high correlation: r-value of 0.6 to 1.0 (or −0.6 to −1.0)

3.2.8. Terminology used in the guideline

The 2004 guideline used the internationally agreed terms ‘type 1 diabetes’ and ‘type 2 diabetes’ rather than ‘insulin-dependent diabetes mellitus’ and ‘non-insulin-dependent diabetes mellitus’, respectively. This terminology has been retained in the 2015 update.

Similarly, the 2015 update relates to the care of children (people younger than 11 years) and young people (those aged 11 years or over, but under 18 years), as did the 2004 guideline. The following terminology used in the 2004 guideline has been retained in the 2015 update to refer to specific age groups:

• neonates (0 weeks or older and younger than 4 weeks)
• infants (4 weeks or older and younger than 52 weeks)
• pre-school children (1 year or older and younger than 5 years)
• primary school children (5 years or older and younger than 11 years)
• young people (11 years or older and younger than 18 years)
• adults (18 years or older).