Transcript Qualitative research synthesis

Research synthesis:
What, why and how?
Dr Ernestina Coast
Research synthesis
 What
is known from what has been done?
 NOT
 What
has been done?
Many different types of research
synthesis
 Systematic
review
 Meta-ethnography
 Meta-analysis
(qualitative)
(quantitative)
What is research synthesis?
A
comprehensive review that looks for, and
evaluates, existing research evidence.
 NOT
 “Traditional”
literature review
Characteristics
 Rigorous
A
methods
“scientific” methodology
 Replicable
 Minimise
 Answer
/ accountable / updateable
bias and error
to focussed question(s)
Why useful?
 Balanced
inference on best available
evidence
 NOT
 Description
of everything on the subject
Quantitative systematic reviews
 Well-established
 Well-funded
 National
and international collaborations
 Associated with RCTs
 Associated with intervention research i.e.:
“What works”?
 A cornerstone of evidence-based practice
and policy
Research synthesis: 5 steps
1.
2.
Decide what question(s) you are trying to
answer
Identify a protocol

3.
What evidence are you prepared to include?
Find all of the relevant evidence

Data mapping an output in its own right?

4.
5.
Identify major knowledge gaps
Appraise the quality of the evidence
Decide what the evidence means
Recent UK example: DiCenso et al,
2003
 Objective:
To review the effectiveness
of primary prevention strategies aimed
at delaying sexual intercourse,
improving use of birth control, and
reducing incidence of unintended
pregnancy in adolescents.
 Study
selection: 26 trials described in
22 published and unpublished reports that
randomised adolescents to an intervention
or a control group (alternate intervention or
nothing).
 Data
extraction: Two independent
reviewers assessed methodological quality
and abstracted data.
Effect of interventions on whether adolescents used birth control the last
time they had sexual intercourse
DiCenso, A. et al. BMJ 2002;324:1426
Copyright ©2002 BMJ Publishing Group Ltd.
 Qualitative
 “insidious
research as postscript
discrimination”
 Via
 “institutionalised
quantitativism”
Booth (2001)
 Meta-ethnography
Education
 Nursing

Are qualitative research (data) appropriate for
research synthesis?




Unlikely to use RCT design
Less likely to have been used as methodology for
intervention research
Where to search for evidence?
“qualitative research clearly has a role…but it is
unclear how systematic reviews of qualitative
research can contribute…..”
5 steps revisited: qualitative evidence
1.
Decide what question you are trying to answer
2.
Identify a protocol

3.
Find all of the relevant evidence



4.
Likely to involve lots of hand searching
Language
Qualitative research tends to be less well indexed than
quantitative research
Appraise the quality of the evidence

5.
What evidence are you prepared to include?
Different or same as for quantitative evidence?
Decide what the evidence means
 Uniqueness
reflexivity
of the ethnographic method is
 Richness
of insight: an emphasis on
contradictory cases
 Existence
of multiple views/ perspectives
Alternative interpretations
Potentially competing explanations
 Research
synthesis very limited in forms of
evidence that are incorporated
 Need
robust ways of incorporating
qualitative evidence into research
synthesis
A
more holistic view of what constitutes
“evidence”
Alternatively….
 Policy
issues not the business of academic
researchers
Try writing that on a funding proposal……
 Role
of an academic researcher is not to
seek common ground
 Post-modernity
Absolute
evidence does not exist
Synthesis of qualitative research
 Bayesian
approaches?
 Use
qualitative evidence to identify
variables for synthesis then attach weights
to strength of quantitative evidence
associated with these variables
A
proliferation of checklists
 Meta-ethnography
a sign of
“methodological maturity”?
 Not
a call for uncritical translation of
quantitative research synthesis approaches
 Stand-alone
or integrated
Quantitative supremacy?