Introduction to Evidence-Based Health Care and the Systematic Review of Evidence
Over view • Evidence Based Health Care • The Joanna Briggs Institute (JBI) • The JBI Model of Evidence Based Practice • The Systematic Review Process
Evidence-based Health Care (EBHC) • ‘the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. Evidence-based clinical practice requires integration of individual clinical expertise and patient preferences with the best available external clinical evidence from systematic research and consideration of available resources’(Guyatt et al., 2008:783).
Evidence-based Health Care (EBHC) • Evidence based health care takes place when decisions that affect the care of patients are taken with due weight accorded to all valid, relevant information (Hicks, 1997)
Evidence-based Practice (EBP) • ‘EBP is clinical practice in which patient management decisions are consistent with the principles of evidence-based health care. This means that decisions will be, first of all, consistent with the best evidence about the benefits and downsides of the alternative management strategies. Second, decisions will be consistent with the values and preferences of the individual patient’ (Guyatt et al., 2008:783).
Evidence-based Health Care (EBHC) Needs and preferences of patients & clients EBHC Professional expertise, skills & judgment Best available research evidence
Evidence = knowledge arising : Reconceptualising Evidence • From experience • From acknowledged experts • From learned/official bodies • From experimental research • From any rigorous research studies
Evidence is… • ‘…the available facts, circumstances etc supporting or otherwise a belief, proposition etc or indicating whether a thing is true or valid…’ (Pearsall and Trumble, 1995) • “…any statement, record, testimony which tends to prove the existence of a fact in issue” (Nygh and Butt 1997, p435)
The Joanna Briggs Institute • Evidence Based Practice • Research Institute since 1996 • Royal Adelaide Hospital and the University of Adelaide • Not-for-profit • 60+ Centres and Groups, >5000 members in over 47 countries • Global Leader
The Joanna Briggs Institute • International collaboration of health scientists, health professionals and health researchers • To improve global health through providing point-of-care access to: • Evidence databases • Decision support systems • Implementation, evaluation and continuous improvement tools
JBICOnNECT • Clinical Online Network for Care and Therapeutics
The Systematic Review • Also called research synthesis: has some characteristics of literature review • Is an ‘attempt to integrate empirical research for the purpose of creating generalisations’ to: • ‘produce statements about evidence that are neutral in perspective’ • ‘uncover all the evidence’ • Explicit and exhaustive reporting of the methods used in syntheses (Cooper & Hedges, 2009:6-7)
Systematic Review • ‘a review that has been prepared using a systematic approach to minimising biases and random errors’ (Egger et al., 2001:5) • ‘is an attempt to minimise the element of arbitrariness … by making explicit the review process, so that, in principle, another reviewer with access to the same resources could undertake the review and reach broadly the same conclusions’ (Dixon et al., 1997:157 quoted by Seers, 2005:102).
Meta-analysis • Quantitative evidence • Use of statistical methods of combining the results of various independent, similar studies • More precise calculation of one estimate of treatment effect than could be achieved by any of the individual, contributing studies • Only forms a part of the systematic review in which it appears
Meta-synthesis • Qualitative analysis of a number of independent qualitative research studies and text • Use of qualitative methods of combining the findings of individual studies • Only forms a part of the systematic review in which it appears
Comprehensive/mixed method Review • Combines both quantitative and qualitative findings and addresses both forms of evidence
Characteristics of a Systematic Review • a clearly stated set of objectives with pre-defined eligibility criteria for studies • an explicit, reproducible methodology • a systematic search that attempts to identify all studies that would meet the eligibility criteria • an assessment of the validity of the findings of the included studies • a systematic presentation, and synthesis, of the characteristics and findings of the included studies • (Green et al., 2008:6)
Steps in a Systematic review • Formulate review question • Define inclusion and exclusion criteria • Locate studies • Select studies • Assess study quality • Extract data • Analysis/summary and synthesis of relevant studies • Present results • Interpret results/determining the applicability of results (Egger & Smith, 2001:25; Glasziou et al., 2004:2)
Systematic Review • The notion of and methods for establishing credibility in systematic reviews has been extensively developed and debated • In terms of quantitative evidence: • Emphasis on reducing bias and increasing validity • degree of credibility established through critique and by applying levels of evidence • In terms of qualitative evidence: • Emphasis on rigour of research design and transferability • Degree of credibility established through critique and by applying levels of credibility
Standard format for protocols • Background • Objectives • Review Question • Criteria for considering studies for this review • Types of participants • Types of interventions • Types of outcome measures • Types of studies • Search strategy • Methods of the review • Assessment of methodological quality • Data extraction • Data synthesis • References
Review Question(s) • Like any research project, the systematic review has a research question or hypothesis. • Should be specific and focused. • Addresses: PICO • Provides the basis for development of the inclusion criteria.
“PICO” (Quantitative/causal relationships) P - population I - intervention C - comparison O - outcome “PICo” (Qualitative/experential) P - participants I - phenomena of Interest Co - context Review Question(s)
Example of Review Questions • Evidence of Effectiveness: • In adults aged over 65 years with a venous ulcer on the lower leg, what effect does the application of moist wound dressings compared to dry dressings have on healing rates?
Inclusion Criteria • Operationalises the review question. • Provides the details of what studies are to be included in the review. • Should cover: • Population • Intervention/ comparison or activity/issue • Outcome • Study design • May also list what is to be excluded: • Specific populations • Language • Setting
Inclusion Criteria-Example • Participants/Population • adults at risk of developing mucositis resulting from chemo/radio-therapy • Intervention • those used to prevent mucositis • Outcome Measures • prevalence of mucositis • oral infection rates • Type of Studies • randomised controlled trials
Search Strategy • Stepwise strategy to identify all relevant literature • Databases to be searched • Search terms • Time frames
Methods of the review • Assessment of methodological quality • Critical Appraisal • Data extraction • Data synthesis
Protocol • Reviewers • Search strategy • Bibliography - retrieved studies • Bibliography - non selected studies