9 Summary of the methods used to develop this guidance

Introduction

The reviews include full details of the methods used to select the evidence (including search strategies), assess its quality and summarise it.

The minutes of the Public Health Advisory Committee (PHAC) meetings provide further detail about the Committee's interpretation of the evidence and development of the recommendations.

Guidance development

The stages involved in developing updates of public health programme guidance are outlined in the box below.

1. Update proposal prepared

2. Expert meeting to discuss update proposal

3. Stakeholder consultation on update proposal

4. Final update decision made

5. Evidence reviews undertaken and submitted to PHAC

6. PHAC produces draft recommendations

7. Draft guidance (and evidence) released for consultation and for field testing

8. PHAC amends recommendations

9. Final update guidance published on website

10. Responses to comments published on website

Key questions

The key questions were established as part of the scope. They formed the starting point for the reviews of evidence and were used by the PHAC to help develop the recommendations. The overarching questions for the original guidance were:

Question 1: What level of coverage should needle and syringe programmes provide to keep HIV prevalence low and to reduce the prevalence of hepatitis C among people who inject drugs?

Question 2: What type of needle and syringe programmes are effective and cost effective in reducing the transmission of blood-borne viruses and preventing injecting- site bacterial infections among people who inject drugs?

Question 3: Which additional harm-reduction services offered by needle and syringe programmes are effective and cost effective in reducing the transmission of blood-borne viruses and preventing the occurrence of injecting-site bacterial infections among people who inject drugs?

Question 4: Are needle and syringe programmes more effective and cost effective if they are offered in parallel with, or alongside, services that provide opiate substitution therapy?

These questions were used to update the original review of the evidence.

Subsidiary questions for the guidance update included:

1. What types of needle and syringe programme are effective and cost-effective for reducing the prevalence of HIV, hepatitis C and other blood-borne viruses, and morbidity and mortality relating to injecting drug use in people who inject image- and performance-enhancing drugs?

2. Which additional harm-reduction services offered by needle and syringe programmes are effective and cost-effective for reducing the prevalence of HIV, hepatitis C and other blood-borne viruses, and morbidity and mortality relating to injecting drug use in people who inject image- and performance-enhancing drugs?

3. What do people who inject image- and performance-enhancing drugs identify as suitable types of needle and syringe programme, and what do they believe to be a suitable level of coverage of needles, syringes and other types of injecting equipment?

4. What are their views and perspectives on, and experiences of, different types of needle and syringe programme?

5. How do the key harms associated with injecting drug use among people under 18 differ from those for older populations who inject drugs?

6. What are the barriers to service use among young people who inject drugs?

7. What are the social factors shaping patterns of use, perceptions of risk, harm, benefit and pleasure, and help-seeking (especially the use of needle and syringe programmes) among young people who use drugs?

Reviewing the evidence

Evidence reviews for the original guidance

Two reviews of the evidence were conducted for the original guidance:

  • 'Injecting equipment schemes for injecting drug users: qualitative evidence review'

  • 'A review of the effectiveness and cost-effectiveness of needle and syringe programmes for injecting drug users'

Economic modelling for the original guidance

The results of economic modelling are reported in:

Evidence reviews for the update

Two reviews of the evidence were conducted:

  • Update of NICE guidance PH18 on needle and syringe programmes: PIEDs review

  • Update of NICE guidance PH18 on needle and syringe programmes: qualitative and quantitative review updates

Identifying the evidence

Several databases were searched between January and March 2013 for all types of study published from 1990 onwards. See Update of NICE guidance PH18 on needle and syringe programmes: PIEDs review and Injecting drug use among young people – risk, harm and factors affecting access to services: a systematic review of the evidence. They were also searched for all types of study published from 2008 onwards. See Update of NICE guidance PH18 on needle and syringe programmes: qualitative and quantitative review updates.

In addition, a call for evidence via the NICE website was used to generate further studies

Selection criteria

Inclusion and exclusion criteria for each review varied and details can be found in the Supporting evidence.

Quality appraisal

Included papers were assessed for methodological rigour and quality using the NICE methodology checklist, as set out in Methods for the development of NICE public health guidance. Each study was graded (++, +, −) to reflect the risk of potential bias arising from its design and execution.

Study quality

++ All or most of the checklist criteria have been fulfilled. Where they have not been fulfilled, the conclusions are very unlikely to alter.

+ Some of the checklist criteria have been fulfilled. Those criteria that have not been fulfilled or not adequately described are unlikely to alter the conclusions.

− Few or no checklist criteria have been fulfilled. The conclusions of the study are likely or very likely to alter.

Summarising the evidence and making evidence statements

The review data was summarised in evidence tables (see the reviews in Supporting evidence).

The findings from the reviews were synthesised and used as the basis for a number of evidence statements relating to each key question. The evidence statements were prepared by the external contractors (see Supporting evidence). The statements reflect their judgement of the strength (quality, quantity and consistency) of evidence and its applicability to the populations and settings in the scope.

Policy review and consensus exercise

Several databases and key websites were searched in January 2013 for policy documents from 1990 onwards. In addition key websites were searched. In addition, a consensus development exercise was conducted through a series of interviews, a 1-day meeting and a subsequent Delphi study. See Analysis of national and local policy and protocols on the delivery of needle and syringe programme services to young people under 18: policy review and consensus development exercise.

Cost effectiveness

See Supporting evidence for details of the cost effectiveness evidence used to support the original guidance. No additional analyses were undertaken for this update.

Fieldwork

Fieldwork was carried out to evaluate how relevant and useful NICE's recommendations are for practitioners and how feasible it would be to put them into practice. It was conducted with: commissioners, criminal justice workers, needle and syringe programme providers and workers in specialist needle and syringe programmes for young people, pharmacies and public health staff.

The fieldwork comprised a focus group and interview analysis carried out by AddAction Research and Development .

The main issues arising are set out in section 10 under Fieldwork findings. Or see Needle and syringe programme fieldwork.

How the PHAC formulated the recommendations

At its meetings in June, July and December 2013, the Public Health Advisory Committee (PHAC) considered the evidence and cost effectiveness to determine:

  • whether there was sufficient evidence (in terms of strength and applicability) to form a judgement

  • where relevant, whether (on balance) the evidence demonstrates that the intervention or programme/activity can be effective or is inconclusive

  • where relevant, the typical size of effect (where there is one)

  • whether the evidence is applicable to the target groups and context covered by the guidance.

PHAC developed recommendations through informal consensus, based on the following criteria:

  • Strength (type, quality, quantity and consistency) of the evidence.

  • The applicability of the evidence to the populations/settings referred to in the scope.

  • Effect size and potential impact on the target population's health.

  • Impact on inequalities in health between different groups of the population.

  • Equality and diversity legislation.

  • Ethical issues and social value judgements.

  • Cost effectiveness (for the NHS and other public sector organisations).

  • Balance of harms and benefits.

  • Ease of implementation and any anticipated changes in practice.

Where possible, recommendations were linked to evidence statements (see The evidence for details). Where a recommendation was inferred from the evidence, this was indicated by the reference 'IDE' (inference derived from the evidence).

  • National Institute for Health and Care Excellence (NICE)