Secondary Data Analysis: Systematic Reviews & Associated Databases

Prof. Eileen Savage

OMCYA Keeping Children Safe Summer School,

12th – 16th September 2011,

UCC.

What is a Systematic Review?

a concise scientific investigation, with pre-planned methods that summarise, appraise, synthesise and communicate the results of multiple primary studies (Cooke et al, 1997; Centre for Reviews and Dissemination, 2008).

ie Research on Research with findings of existing data becoming raw data

Differs from a narrative review/

traditional literature review

Traditional Review vs. Systematic Review (Nasseri-Moghaddeam & Malekzadeh 2006)

Growth of Systematic Reviews

Systematic Reviews – Origins of Growth Expanding volume of

published & unpublished literature

Conflicting findings across studies leading to ‘uncertainty’

Contributes to Evidence Based Movement

When to Do a Systematic Review When there is ‘uncertainty’ about the effectiveness of

interventions in practice When key questions remain unanswered e.g. about

treatments, interventions, practices, experiences etc… To inform practice/policy with best available research

evidence To identify what is known/not known in an area to guide

future research (includes research methods)

(Petticrew & Roberts 2007)

Where to find a Systematic Review Peer Reviewed Journals (search bibliography databases) Cochrane Database of Systematic Reviews (Cochrane Library;

several Groups) Database of Abstracts of Reviews of Effects (DARE) Health Technology Assessment Database NHS Economic Evaluation Database The Campbell Collaboration Library (Groups e.g. Crime & Justice;

Education; Social Welfare; Methods; Communication & internationalization; Users Groups.

The Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-Centre), University of London. (Education; Health Promotion; Employment; Social care; Crime and Justice)

Others

Structure of Systematic Review e.g.

Introduction/Background Questions/Aim & Objectives Criteria for considering studies Search Methods Methods of the Review (e.g screening reading

papers; quality assessment; data extraction) Results Discussion Conclusions

Criteria for Including/Excluding Studies Types of Studies (see hierarchy of evidence)

Types of Participants

Types of Outcomes

Link to Questions being asked

Hierarchy of Evidence

Search Method

Search Terms Databases +/- Hand searching+/- Reference lists+/-Grey Literature+/- Contacting authors (Refer to Booth et al on standards for Reporting Search Methods)

   

Date of Search 30th March 2011Years Covered January 1990 to March 2011

Complete Strategy

1. cystic fibrosis. ti,ab,de.2. mucoviscidosis. ti,ab,de.3. 1 or 24. 'clinical trial'. ti,ab,de.5. 'trial'. ti,ab,de.6. random*'. ti,ab,de.7. 4 or 5 or 68. educat*. ti, ab, de.9. program*. ti,ab,de.10. 8 or 911. self care ti, ab, de.12. selfcare. ti,ab,de.13. self management. ti, ab,de14. manag*. ti, ab,de.15. 11 or 12 or 13 or 1416. 10 or 1517. 3 and 7 and 16 

   Date of Search 30th March 2011

Years CoveredJanuary 1990 to March 2011

Complete Strategy

1. cystic fibrosis.TX.2. mucoviscidosis.TX.3. 1 or 24. clinical trial.PT.5. trial.TX.6. random*TX.7. 4 or 5 or 68. educat*.TX.9. program*TX.10. 8 or 911. self care.TX.12. self-care.TX.13. selfcare. TX.14. self management. TX.15. self-management.TX.16. manag*.TX.17. 11 or 12 or 13 or 14 or

15 or 1618. 10 or 1719. 3 and 7 and 18

 

Language Restrictions None

Search Strategy: CINAHL with Full Text (EBSCO)

Search Strategy: Embase (Elsevier)

Methods – Screening for Inclusion/ Exclusion

Titles & Abstracts – In/Unsure/Out Read in full –> in/unsure /out

Quality Assessment of Individual Studies Quality threshold for inclusion ie exclude poor

quality studies Assessment of Quality may be part of SR

How

- No –’gold standard’ exists - Checklists available e.g. CASP - Quality Scales/Criteria

Data Extraction

Use a data extraction form (s)

2 or more reviewers / cross-check

Extract details relevant to Questions/ Objectives

Present raw data in report – table format

Data Analysis & Synthesis Collation & summary of results Present in tabular form/forest plots/other +

descriptive narrative account +/- Meta-analysis, if appropriate (not possible

with heterogeneity ie cannot pool apples with oranges for the purpose of statistical analysis as one data set)

Results, Discussion, Implications

Critical Appraisal of Systematic Reviews

The PRISMA Statement: standards for reporting SRs & Meta-analyses

Critical Appraisal Tool Kit for SRs (CASP)

Website on Critical Appraisal Tools (covers a range of methods) At:

Division of Health SciencesInternational Centre for Allied Health Evidence

http://www.unisa.edu.au/cahe/Resources/CAT/default.asp

References To follow