STUDY DESIGNS FOR HEALTH ARE QUESTIONNAIRES

Question 1

What is evidence based medicine

Answer 1

The conscientious, judicious and explicit use of current best evidence when making decisions about the care of individual patients

Question 2

What 3 sectors make up EBM

Answer 2

• Clinical research
• eliciting patient preferences
  -Clinical experience

Question 3

Give two examples of harm caused by lack of evidence

Answer 3

• Sudden infant death syndrome (SIDS)
• Thalidomide

Question 4

What are the two types of epidemiological studies

Answer 4

• Descriptive
• Analytical

Question 5

Why is the AAAA framework important? (3)

Answer 5

• Medical knowledge is continuously evolving
• Medical profession frequently fails to use effective treatment
• Keeping up to date is a lifelong commitment for a doctors

Question 6

What are epidemiological studies and what are they used for?

Answer 6

• Studies that are descriptive/ observational
• Used to answer questions about frequency and pattern of diseases e.g how much disease and distribution of disease
• Used for hypothesis generation

Question 7

What are the two types of descriptive studies?

Answer 7

• Case report
• Case series
• Cross sectional studies
• Ecological studies
• Analytical studies

Question 8

What is the AAAA framework

Answer 8

It is a way of finding and critically appraising evidence. The 4 As stand for
- Assess - what type of healthcare question - what type of study
- Access - Finding the best evidence (validity and relevance)
- Appraise - evaluating the quality of evidence and interpreting the results
- Act - is the evidence relevant to my clinical practice and should this evidence change my practice

Question 9

What are case reports

Answer 9

A detailed report of an unusual ‘condition’ or ‘occurence’ in a single patient

Question 10

What are case series

Answer 10

A detailed report of an unusual ‘ condition’ or ‘occurrence’ in a series of patients

Question 11

What are cross sectional studies, what are they also known as?

Answer 11

• A study where information is collected in a planned way from individuals in a defined population at one point in time
• Also known as prevalence study, incidence study, survey

Question 12

What is an example of a cross sectional study

Answer 12

• Office for national statistics
• People, populations and community surveys
• Health and social care

Question 13

What is the definition of an ecological study?

Answer 13

• A study in which information is collected from a whole population to compare disease frequencies

Question 14

How can an ecological study be carried out

Answer 14

• In one population at different points in time
• Between different populations at the same period of time

Question 15

What is an analytical study and what is the aim of it?

Answer 15

It is an explicit comparison of two or more groups of individuals. Its aim is to establish whether an exposure causes an outcome (cause and effect)

Question 16

What are the two types of analytical studies

Answer 16

• Observational (cohort and case control)
• Interventional/ experimental (intervention and clinical trials)

Question 17

What are analytical observational studies

Answer 17

They are natural experiments - the researcher isn’t in control of a persons exposure to something that causes harm or disease. They are not in control because of ethical or logistical constraints

Question 18

Describe the two types of analytical observational studies

Answer 18

• Case control - this is where a study starts with the identification of the outcome (disease). Those with the condition are compared to those without (control group)
• Cohort - study starts with the identification of the exposure e.g risk factor. Those with the risk factor are grouped and compared against those who don’t have the risk factor. If the incidence of outcome is higher in those with the risk factor compared to those without then there might be a risk factor

Question 19

Examples of cohort studies (4)

Answer 19

• Nurses health studies
• Whitehall studies
• Framingham heart studies
• National child development study (UK)

Question 20

Give 3 pro’s of case control studies

Answer 20

• Can investigate multiple exposures
• Don’t have to wait for outcome to occur
• Groups for comparison are based on the presence of the outcome and this overcomes the problem of rare outcomes

Question 21

What is a con of case control studies?

Answer 21

Can only investigate one outcome

Question 22

Give one pro of cohort studies

Answer 22

Can investigate multiple outcomes because exposure to one thing can result in lots of different outcomes

Question 23

Give 3 cons of cohort studies

Answer 23

• Can only investigate one exposure
• Have to wait for outcome after exposure - this can result in problems with follow up
• For rare outcomes, a lot of exposed individuals would need to be recruited

Question 24

What is a controlled clinical trial and what are they used for?

Answer 24

An experimental study where researchers decide whether participants will receive the new intervention being tested or receive a control treatment e.g placebo. They are used to investigate effectiveness

Question 25

Advantage of randomised controlled clinical trials (RCTs)?

Answer 25

Increases internal validity

Question 26

What is the pre-requisite for an RCT

Answer 26

• There is genuine uncertainty about which treatment is best
• Equipoise - balance of interests
• The new treatment will do more harm than good

Question 27

Give the order of the hierarchy of evidence

Answer 27

• RCT
• Cohort studies
• Case control studies
• Case series and reports
• Expert opinion and anecdotal evidence

Question 28

What is qualitative research?

Answer 28

• Collection of non numerical data about peoples subjective understandings of their lives and experiences
• in depth study of small amount of individuals, doesn’t aim for generalisability
• Interviews, direct observations