Introduction to ‘EBSI’. Methodologies for a new era summer school School of Applied Social Studies, University College Cork 20 June 2011 Dr Paul Montgomery. Why Evidence-Based Social Intervention ?. Why practice needs sound evidence-base ethical imperative to do more good than harm
Methodologies for a new era summer school
School of Applied Social Studies, University College Cork
20 June 2011
Dr Paul Montgomery
If we want to intervene (interfere) in people’s lives, and spend large sums of money doing this, then we have an ethical duty to show that we are basing our interventions on the very best possible available evidence.
If not, we may at best be wasting the precious time, money and hopes of vulnerable clients
At worst we may be doing more harm than good.
“ the conscientious, explicit and judicious use of best currently available evidence, integrated with client values and professional expertise, in making decisions about the care of individuals”
- Can also apply to planning of services -
(adapted from Sackett et al., 2000)
Client part of decisions – their preferences, experiences, values etc, integrated with evidence and expertise
Share evidence with client, otherwise informed consent meaningless. Need honesty, openness re. state of knowledge.
Empowering if this is done.
These principles are applicable at a community level.
Not ‘I know best’; lifelong learner, questioner, always updating
Client as part of decision making team
Sharing knowledge and expertise
Based on respect for client and their knowledge
1. Formulating answerable questions
2. Searching literature
3. Critical appraisal of research
4. Applying findings to practice
5. Evaluation of outcome
Nature & prevalence of problem. Who is it a problem for?
Trials - RCT’s
Evidence based practice
Judicious application of
client / organisation
‘Gold standard’ research design for evaluating intervention which attempts to minimise sources of bias
Allocates participants at random to intervention and comparison groups (this is the defining feature)
Uses same, meaningful reliable assessments before and after intervention
Double or single ‘blind’ if possible - reduces a very important source of bias
An overview or summary of primary studies, carried our according to an explicit set of aims & methods - so review is reproducible.
e.g. a set of RCT’s all addressing a similar question, or a set of studies about prevalance or causes or screening.
Cabot carried out first major RCT in social work in 1930’s Massachusetts, USA (Powers & Witmer, 1951; McCord, 2001)
- theory driven intervention - based on knowledge of risk factors for crime
650 boys under 12 (mean age 10) 1935. 506 after WW2
Risk of delinquency due to poor, high crime areas
Placed in matched pairs (similar age, SES etc )
Randomly assigned one of pair to intervention, other to control group
Intervention lasted 5.5 years on average
Follow-up: mid 1940’s; late 1970’s, age 47, 98% traced.
Outcomes: records of courts, death, mental illness;
Careful records of contacts and interventions kept.
6-10 years later: found no differences between groups in behaviour or delinquency rates
Note two different methods give same message.
35 year follow up: age 47, traced 98% of sample!
using state records, found intervention boys more likely to have negative outcomes including: serious convictions, deaths by age 35, serious mental illness, compared to control group.
These gave youngsters a taste of what prison was like, adopted in 38 states
Petrosino et al (2002) Campbell/ Cochrane library
1. What sorts of interventions appear more likely to harm - or to do no good?
2. What are the mechanisms of harm?
Or - What is actually is going wrong in this intervention?
NB We also want to know this with interventions that go well- what are the active useful ingredients- (mediators of intervention)
Limitations apparently based on misconstrual (‘straw man’):
Social science/ intervention is different from medicine:
Does EBP work? Does it lead to better outcomes for people?