(10) Research methods and evidence-based practice in clinical psychology Flashcards
What is evidence based medicine? EBM
- The concept is about making sure that when decisions are made they are made on the basis of the most up-to-date, solid, reliable, scientific evidence.
- In the case of medicine or health care, these are the decisions about the care of individual patients.
What are the aims of EBM?
Aim: aims to apply the best available evidence gained from the scientific method to medical decision making.
-How? By ranking evidence based on: the quality of studies, the strength of their findings
NICE guidelines for Mental Health and example?
- 23 complete guidelines
- Example: three sets of guidelines for depression:
- Adults
- Children and young people
- Depression with a chronic physical health problem
What is the process of EBM reviews?
- Search
- Read, include & exclude studies.
- Appraise, according to set criteria to establish quality.
- Synthesise where possible, by pooling results across studies
Based in appraisal (How is it assessed?)
- Of published papers: Depends in quality of search And on good critical criteria
- Laboratory tests
- Clinical experience
How are Randomised Controlled Trials assessed?
- The gold standard
- Randomisation: Controls for unknown bias and confounding
- Blinding: single and double
- Control group
How are RCT’s often flawed?
- Incomplete randomisation (drop-out, allocation bias)
- Length of trial? (e.g. dynamic versus behaviour therapy)
- Blinding patients? Assessor?
- Choice of control group? (Are waiting lists ethical?)
- Choice of outcome? (Days off work might be a primary outcome to government, but not to patients…)
A randomized clinical trial has four elements:
- A treatment group and a control group
- Randomization
- Blinding
- Ethics
What are a treatment group and control group in a radomized clinical trial?
A treatment groupand acontrol group.The treatment group receives an experimental treatment. The control group might be given no treatment at all, aplacebo, or “treatment-as-usual.” The idea is that the control group gives the clinician something to compare the experimental results to.
Why is randomization used?
Randomizationto allocate patients to one of the two groups. This randomization is normally performed by a computer.
Why is blinding used?
Blindingto prevent the patient or researcher from knowing what group they are assigned to. In a blind trial, the participants don’t know what treatment they are receiving (which may be a placebo). In a double blind trial, neither the participant nor the researcher knows which group the participant is in. Trials are often double-blinded to avoidselection biason the part of the researcher.
RCT can be problematic when…
- Clearly successful intervention (implemented already or reviewed in meta-analysis): replace with head to head or non-inferiority trials.
- Unethical (AZT)
- Very large subject groups needed, or when cases are very rare (Examining the effect of counselling on ‘unifying’ personality in people with split personality)
- Arguably, when treatment cannot be standardised (think which psychological model would fare better for standardisation)
What are cohort studies?
- Cohort studiesare a type of medical research used to investigate the causes of disease, establishing links between risk factors and health outcomes.
- Cohort studiesare usually forward-looking - that is, they are “prospective”studies, or planned in
What is a famous cohort study?
Hill & Dolls’ famous ‘Doctors Study’ started in 1951, finished in 2001, and provided strong evidence the smoking was closely linked to lung cancer.
Aspects of a cohort study
- Longitudinal.
- Baseline measures.
- No intervention, observe follow up over time, measure outcome.
- Inform about causality.
- Often large, costly, and time consuming
