Making Research Count: Dealing with Bias and Uncertainty

Question 1

What is Research?

Answer 1

o Aim:
Develop new treatments & information to benefit people.
o Two broad areas:
Pre-clinical, plus Clinical & Healthcare
o Pre-clinical research:
Basic or bench research
- Laboratories: Invertebrates, in vitro, and animal experimentation;
- Underpins clinical and healthcare research.
o Clinical & Healthcare Research:
Human participants
- Patients & healthy volunteers;
- Study of illness and health;

Question 2

Bench to Bedside

Answer 2

Translates findings pre-clinical research into new treatments & information to benefit people.

Question 3

What are the types of research?

Answer 3

o Quantitative: Measure numerical data in small group of people; specific study design, analyse, generalise findings to population.
o Qualitative: Understanding underlying reasons, opinions, & motivations; non-numerical data.
o Typically regarded as being types of research: quantitative and qualitative research. Much debate as to what they consist of, and their use; there are no clear cut definitions. Considerable overlap in definitions.

Question 4

Describe Quantitative Study Designs

Answer 4

Observational Designs: No intervention.
❖ Record behaviours, attitudes & symptoms - Naturalistic:
➢ Investigating associations;
➢ Eating red meat & development colon cancer.
❖ Example: Cohort studies; Cross-sectional studies (inc. surveys).
Experimental Designs: (Factorial Designs)
❖ Researcher controls or introduces factor:
➢ Effects of different diets on weight of mice;
➢ Effectiveness of new antidepressant drug.
❖ Record effects of intervention on outcomes:
➢ Investigate sources variability.
❖ Example: Trials (Future lecture)

Question 5

What are the methods of sampling?

Answer 5

(Simple) Random Sampling
o Sampling frame (list) for population:
- Every member has equal probability of selection;
- Representative sample (large enough);
- Feasible? Cost and time? Theoretical?
o Convenience Sampling: Participants convenient to access.
- e.g. Single hospital or clinic;
- Representative sample? Selection bias & Volunteer bias?
o Example 1: Mixture Multicentre and Convenience Sampling ≥ 1 Organisations.
o Multicentre: Sample ↑ representative population.

o Dangers of convenience sampling (and to some extent any sampling including multicentre)

Question 6

What are the types of bias?

Answer 6

Response Bias:
❖ Particular problem: Self-report outcomes.
❖ Systematic difference between participant response & “truth”.
Assessor Bias:
❖ Systematic difference between assessor measurement of
participant & “truth”.
Caution: Difficult to remove, only minimise biases (generally).
❖ Experimental Designs: Aspects of methodological designs.
❖ Observational Designs: Harder to control.
Hawthorne Effect: Change in participants’ behavior due to
attention received in study.
❖ Change in behaviour afterwards?

Question 7

What is a hypothesis?

Answer 7

Research: Hypotheses driven.
Research Hypothesis: Initiates the research.
❖ Typically based on anecdotal evidence;
➢ “Believe dietary protein affects weight gain in mice”.
❖ Objective evidence required: Undertake research;
➢ Collect data (sample) as evidence (for population).
Statistical Hypotheses (Traditional) (Future lecture)
Hypotheses: Population-based.
Null: No difference exists between factor levels in outcome;
Alternative: Difference exists between factor levels in outcome;
Data (evidence): Lend support to Null or Alternative.
❖ Cannot (dis)prove a hypothesis;
➢ Philosophy: Based on sampling.