Systematic Reviews Practicalities and Realities

Alison Brettle, Research Fellow (Information) Salford Centre for Nursing, Midwifery and Collaborative Research University of Salford

Session Overview

  Practical overview of systematic reviews and what you need to conduct one Discussion

What is a systematic review?

    An overview of primary research studies conducted according to explicit and reproducible methodology A rigorous method of summarising research evidence Shows what we know and don’t know about a topic area Provides evidence of effectiveness (or not) by summarising and appraising relevant evidence

Systematic reviews aim

    To find all relevant research studies (published and unpublished) To assess each study on basis of defined criteria Synthesise the findings in an unbiased way Present a balanced and impartial summary of the findings taking any flaws into consideration

Systematic review models

  Medical/Health care    Cochrane Collaboration, NHS Centre for Reviews and Dissemination Usually includes “high quality” research evidence – RCTs Often includes meta-analysis (mathematical synthesis of results of 2+ studies that addressed same hypothesis in same way) Social care/Social Sciences    SCIE, EPPI Centre, Campbell Collaboration Often include wider range of studies including qualitative Often narrative synthesis of evidence

Systematic review process

       Define/focus the question Develop a protocol Search the literature (possibly 2 stages scoping and actual searches) Refine the inclusion/exclusion criteria Assess the studies (data extraction tools, 2 independent reviewers) Combine the results of the studies to produce conclusion– can be a qualitative or quantitative (meta-analysis) Place findings in context – quality and heterogeniety of studies, applicability of findings

Task

 You are part of a systematic review team and this is your first meeting. Your task is to draft a protocol by the end of the meeting then present to the other groups

Components of a protocol

    Background/context leading to question Review question Inclusion/Exclusion criteria Methods for       Identifying evidence Selecting studies Extracting studies Assessing quality of studies Synthesising the results Disseminating the findings

Lessons learned in systematic reviews

Workplace physical activity interventions: a systematic review of the research evidence Lindsey Dugdill, Alison Brettle, Claire Hulme, Serena McCluskey, Andrew Long

Background

   Policy Increased PA important for prevention of chronic illness Trend on a worldwide and UK scale that PA levels are declining

 

Objectives

To identify which types of workplace PA intervention were effective in changing PA behaviour for different sectors of the workforce and different types of workplace To ascertain which aspects of intervention design and delivery contributed to effectiveness and contributory motivators, barriers and facilitators

Lesson 1. Focus the question

    More focussed the question, easier to undertake literature search and decide on relevant studies Need to maintain a balance between a clearly defined topic and a meaningful and relevant question Can help scope the literature to help develop the question Refine question as part of review process

Focussing the question

 Options:  empirically led -> literature scoping -> narrowing down topic on the basis of ‘what is there’ in the evidence base   theoretical and conceptual -> concept mapping, explore the meaning given to the concepts, embracing user and carer notions of desired outcomes (based on previous research) themselves central to a ‘social care’ perspective Funder/policy driven

Lesson 2. Scope the literature

   Provides an indication of literature available and what needs to be examined Helps focus the question Helps clarify initial inclusion and exclusion criteria

Lesson 3. Write a protocol

      Plan what you are going to do in the review Set out the background and objectives Outline the resources you will use Establish inclusion/exclusion criteria How will data be extracted (what will be extracted) How will you synthesise literature

Literature search

 12 electronic databases 1996-2007  Selected websites of known organisations  Citation tracking  Could also use   hand-searching of journals “grey” literature

Lesson 4. Use multiple sources of information      Databases only part of the picture Handsearching identifies further references Citation tracking adds more references SMI review – 96 studies (73 databases, 23 handsearching/citation tracking) Counselling – 47 studies (aprox 10 handsearching, 4 citation tracking)

Lesson 5. Refine your search plan as you carry out the literature searches

Theory

  Everything that follows flows smoothly and easily

Practice

 Develop your search plan Modify your approach as the search progresses   Use spiral approach to refine Ongoing discussions within team

Search spiral

   Scoping (initial database searches) Refining (indepth searches of range of sources) Confirming (hand searches, citation tracking)

Inclusion

        Intervention aimed to increase PA Aimed at employed adults

Initiated or endorsed by employer

Outcome measures included a measure of PA Evidence of behaviour change English Published post 1996

Took place in UK, Australia, NZ, Europe

Exclusion

      Self employed or unemployed adults Adults needing specialist advice regarding PA

No evidence of behaviour change or PA measure

Insufficient detail reported in study Cost effectiveness

Located in US or Asia

Lesson 6. How will you refine the inclusion/exclusion criteria?

   Tighter the criteria =  less papers to review BUT  will your review draw any meaningful conclusions?

Focussing the question v quality of studies

Overview of search and appraisal process

Appraisal

      38 papers representing 33 studies Each paper appraised by 1 reviewer, using a standardised protocol, 20% sample reviewed by 2 reviewers and each checked as put on database Quality of papers ++ high, + good, - poor evidence (using protocols/guides provided by NICE) Categorised by intervention and quality rating Summary table Conclusions on the whole derived from those classified as high or good

Lesson 7: Know what you want to find out

      Select your critical appraisal/data extraction tool carefully Make sure it captures the elements that you wish to write about in your final report Think what data need to extract Narrative review v meta analysis Quality of studies – what evidence are you going to include? How are you going to assess the quality Do you need to refine the inclusion/exclusion criteria as you go along?

Findings: published systematic reviews  Inconclusive review level evidence that workplace PA interventions were effective in increasing PA

Findings: Stairwalking

   7 studies (1 high, 2 good, 4 poor) 4 demonstrated that posters and signs can increase stair use in the short term Little evidence of effectiveness

Findings: Walking interventions

    4 studies (2 good, 2 poor) 3 used pedometers (objective measure) All 4 also used self reported counts Evidence that workplace walking interventions can increase daily step counts

Findings: Active travel

  3 studies (1 good, 2 poor) Evidence from 1 study that a walking and cycling to work campaign using written materials can increase walking to work in economically advantaged women

Findings: multi component interventions     16 studies (2 high, 1 good) Wide range of interventions Difficult to attribute which bit of the intervention was causing the effect Limited evidence that counselling has effect on workplace PA

Limitations

    Quality of evidence Exclusion of studies from US and Asia Most of studies took place in large public sector workplaces Reliance on self report measures

Lesson 9. Set up a system to keep track of the review process       Use a package such as reference manager or endnote to keep track of references Large reviews need method of keeping track of data extraction, exel, access or specialised software Update at every stage of the process Compiles references at the end Need a hard copy system too for the actual papers and a system for keeping track of results If you do not know where you are up to – it is unlikely that your review will be systematic

System to manage process – the physical     Putting material into endnote  Direct export from many sources   From a file Direct input How are you going to manage the hard copies What about your notes?

What systems do you use?

Reducing and organising

  Using groups and adding notes to Endnote Using a screening tool (once you’ve ditched the really irrelevant ones)

Data extraction/Critical Appraisal

  Tools     Many widely available Can adapt to suit your own study Could design own Assessing quality – systems available – be explicit if you are going to do this Storing the data    Template in word/Table in word Excel spreadsheet Other?

Useful resources – systematic reviews     Cochrane Collaboration   http://www.cochrane.org/ http://www.cochrane.org/docs/irmg.htm

Centre for Reviews and Dissemination http://www.york.ac.uk/inst/crd/ handbook for conducting systematic reviews,   http://www.york.ac.uk/inst/crd/methods.htm

Searching for systematic reviews http://www.york.ac.uk/inst/crd/revs.htm

EPPI-Centre – Stages of a review  http://eppi.ioe.ac.uk/cms/Default.aspx?tabid=89 SCIE - The conduct of systematic research reviews for SCIE knowledge reviews  http://www.scie.org.uk/publications/details.asp?

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