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Evaluation of effects
Sandra Zwakhalen
June 2018, EDCNS
Health Services Research, Maastricht University
• Research program Ageing and Long-Term care
• Disciplines (>100 employees)- Physicians, Health Economy, Health Policy, Nursing Science,
Care Thechnology, Social Gerontology, Health Technology Assessment etc….
Ageing and Long-Term Careaims to:
1. Develop of knowledge on psychosocial and environmental determinants of health problems, need of care, social participation, independency and quality of life
2. Evaluate of innovative health care programs and interventions for older persons to slow down processes of disablement
3. Implement health care programs and interventions
Major themes
• Effectiveness of care (health care problems), e.g.:- Pain in dementia, Incontinence, Malnutrition, Falls and
injuries, Fear of falling, Mobility, Heart failure, Pressure ulcers, Physical restraints, Disability
• Organisation of care, e.g.:- Patient centered care, Quality of care, Care for frail older
people, Redesigning health care, Small scale nursing homes, Geriatric rehabilitation
Living lab, how
Staff working at both; university and LTC organization
Interdisciplinary; nursing, medicine, psychology…. etc.
Assessing effectiveness
• Research designs• Feasibility to apply designs in
evaluation of complex interventions• Bias• Examples en group work
Assessing effectiveness …. (10 minutes brainstorm ABC exercise to start)
• Thinking about effectiveness, - Brainstorm ABC………
• How can we assess the effectiveness of an intervention?- What research design is viewed as the
‘gold standard’?- Experimental – randomized controlled trials
(Quasi)-Experimental Designs
RANDOMIZED DESIGNS1. Individual-patient randomized controlled trials2. Cluster randomized trials3. Factorial design4. Repeated measures design
SEMI or NON-RANDOMIZED DESIGNS e.g1. Preference trial2. Stepped Wedge Design (Wait-list design)3. Other designs e.g. Time Series Design, Before and After
Design (case control)
Randomized Controlled Trial (RCT)
1. Randomization2. Control3. Manipulation
Key idea of a randomized controlled trial is that we compare groups of participants who differ only with respect to their intervention.
RCT• Example: Effectiveness of morphine following
adenotonsillectomies (T&A) in children
- Randomization- Children admitted for T&A
- Two groups- Experimental/intervention group- Control group
- Intervention- Paracetamol + morphine
In sum:1. Paracetamol + morphine2. Paracetamol + placebo
Why experimental design?
• Internal validity- The extent to which the observed effects
are true for the people in a study- The degree to which a result (of a
measurement or study) is likely to be true and free of bias (systematic errors)
SELECTION BIAS(systematic differences in comparison groups)
PERFORMANCE BIAS(systematic differences in care provided apart from intervention under evaluation)
ATTRITION BIAS(systematic differences in withdrawals)
DETECTION BIAS(systematic differences in outcome assessment)
SOURCES OF BIAS
Target Population (baseline)
Allocation
Intervention Group Control Group
Exposed to intervention Not exposed
Follow up Follow up
OUTCOMES OUTCOMES
Critisism experimental design
• External validity- The extent to which the effects observed in a
study truly reflect what can be expected in a target population beyond the people included in the study
- Generalizability
• Explanatory versus pragmatical RCT’s- Efficacy (does it work in most favourable
circumstances?) versus effectiveness (does it work in everyday practice?)
Why are RCT’s not always suitable
Why are RCT’s not always suitable
• Experimentation may be unnecessary- Efficacy of parachutes, anaesthesia for surgical
operations
• Experimentation may be inappropriate- To measure infrequent adverse events, to prevent rare
events, or measure outcomes in far future
• Experimentation may be impossible- Refusal of clinicians to participate or ethical objections
• Experimentation may be inadequate- Patients in trial are atypical, professionals are
unrepresentative or treatment is atypical
Cluster RCT
• Randomization not on individual level, but on organizational level- E.g., midwife, hospital wards, nursing
homes
• Data collection on individual level- E.g., age, gender, pain, quality of life
Disadvantages?
• Complex (multi-level) analyses, less power
• Complex organisation, time consuming • Large sample needed• Contamination
Factorial design
In which two active treatments A and B, are simultaneously compared to each other and to a control.
Participants are randomized into four groups, who receive either A only, B only, both A and B, or neither.
Factorial design
• Effectiveness morphine and nurses’ systematic pain assessments (SPA)
1. Paracetamol + morphine + SPA2. Paracetamol + placebo+ SPA3. Paracetamol + morphine + no SPA4. Paracetamol + placebo+ no SPA
Repeated measurement designor within subject
• Instead of having one score per subjectmultiple scores are generated for eachcase
• Every subject is his own control
(Quasi)-Experimental Designs
RANDOMIZED DESIGNS1. Individual-patient randomized controlled trials2. Cluster randomized trials3. Factorial design4. Repeated measures design
SEMI or NON-RANDOMIZED DESIGNS e.g1. Preference trial2. Stepped Wedge Design (Wait-list design)3. Other designs e.g. Time Series Design, Before and After
Design (case control)
Preference trial
AssessOutcomes
Receive A
Prefer A
AssessOutcomes
Receive A
AssessOutcomes
Receive B
IndifferentRandomised
AssessOutcomes
Receive B
Prefer B
Stepped Wedge Design
Group task
• Use an example of an intervention study of one of participants.
• CreateResearch question(s)……
(Alternative) design: …..Define participants:……Sampling method: …..Methods of data collection: …..Outcomes and meaures:
Advantages and disadvantages (think of possible bias):…….
Reporting statements
CONSORT for randomised controlled trials STARD for diagnostic accuracy studies STROBE for observational studies PRISMA for systematic reviews of trialsMOOSE for meta-analyses of observational studies
EQUATOR networkhttp://www.equator-network.org/library/translations-of-
reporting-guidelines/
General conclusion
• Experimental designs as the ‘golden standard’
• Not always feasible to use for assessing effectiveness of complex interventions
• Look for the best alternative- Explanatory versus pragmatic trials- Non randomized designs controlling for attrition,
performance and detection bias
• Complex nursing interventions can be evaluated adequately
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