PAS - Clinical Research

Question 1

aims of clinical research

Answer 1

generating evidence for the efficacy and safety of interventions, treatments, and medications

measuring outcomes, prevalence, incidence and risk factors

identify associations between exposures (behaviours/ treatments) and health outcomes/ disease

develop models to predict health outcomes and disease progression

Question 2

pre-clinical research?

Answer 2

basic/ bench research - labs, in vitro and animal experimentation

underpins clinical & healthcare research

Question 3

clinical and healthcare research?

Answer 3

human participants, patients and healthy volunteers - studies illness and heath status

Question 4

objectives of clinical research

Answer 4

standardised measurements for reproducibility and comparability of results

ensure findings can be applied to broader populations beyond the study sample = generalisation

statistical analysis techniques to test hypotheses, measure effect sizes, and estimate confidence intervals

provide data for healthcare decisions - inform clinical guidelines, policy decisions, and best practices in healthcare

Question 5

experimental studies like randomised clinical trials - design? purpose?

Answer 5

participants randomly assigned to an intervention/ treatment or control/ placebo group

determines the causal effect of an intervention by minimizing bias and confounding factors

Question 6

three types of observational studies? purpose?

Answer 6

cohort studies
case-control studies
cross-sectional studies

helps understand the relationships between exposures and outcomes in real-world settings where randomization is not feasible - studies risk factors, disease prevalence and history

Question 7

cross-sectional studies?

Answer 7

analyze data from a population at a single point in time to identify associations between exposures and outcomes

Question 8

case-control studies?

Answer 8

compare people with a specific outcome (cases) to those without (controls) to retrospectively assess exposure to potential risk factors

Question 9

cohort studies?

Answer 9

follows a group of people over time to observe the effect of certain exposures on outcomes - prospective (looking forward) or retrospective (looking back)

Question 10

list different approaches for sampling?

Answer 10

random sampling
stratified sampling
cluster sampling
systematic sampling

Question 11

random sampling?

Answer 11

every individual in the population has an equal chance of being selected, reducing selection bias

Question 12

stratified sampling?

Answer 12

population is divided into subgroups (strata) based on specific characteristics (e.g., age, gender)

random samples are taken from each stratum to ensure representation

Question 13

cluster sampling?

Answer 13

population is divided into clusters (e.g., geographical areas)

random samples of clusters are selected, followed by random sampling within those clusters

Question 14

convenience sampling?

Answer 14

sampling participants convenient to access - e.g. patients in hospital

not necessarily a representative sample, can introduce selection & volunteer bias

Question 15

systematic sampling?

Answer 15

selecting every nth individual from a list of the population after a random starting point

Question 16

effect of selection bias?

Answer 16

when the sample is not representative of the population, leading to skewed results

limits generalisation of findings, can lead to incorrect conclusions

Question 17

effect of information bias?

Answer 17

results from errors in measuring exposure, outcome, or other variables

can misclassify participants and lead to inaccurate estimates of associations - e.g. recall bias in case-control studies

Question 18

effect of confounding bias?

Answer 18

occurs when a third variable is related to both the exposure and the outcome but is not accounted for in the analysis

distorts true relationship between the exposure and outcome, leading to misleading conclusions

Question 19

effect of observer bias?

Answer 19

occurs when researchers’ expectations influence their interpretation of data

affects objectivity of data collection and analysis, especially in qualitative research or subjective measures

Question 20

methods for mitigating bias?

Answer 20

randomisation to prevent selection bias and confounding

blinding to reduce information and observer bias

standardised protocols to ensure consistency in data collection & measurement

statistical adjustment - e.g. multivariate analysis can control confounding variables