Research Methodology

Question 1

Advantages of a Descriptive Study

Answer 1

Hypothesis generation
Health service planning & management

Question 1

Describe descriptive study.

Answer 1

No comparison group. Answers who, what, when, where.

Question 2

The disadvantage of a Descriptive Study

Answer 2

Cannot establish causality

Question 3

Describe a cross-sectional study

Answer 3

Exposure and outcome measured at one point in time
= snap-shot
= prevalence study

Question 4

Advantages of a Cross-sectional study

Answer 4

Relatively cheap & easy
Measure multiple variables at the same time

Question 5

Disadvantages of a Cross-sectional study.

Answer 5

Cannot measure temporality
Cannot measure incidence
Information bias (recall bias); Selection bias

Question 6

How is a cross-sectional study conducted?

Answer 6

Gather information regarding both the presence of a disease and an individual’s exposure status, while simultaneously collecting data on the outcome of interest and exposure status.

Question 7

Describe a Cohort Study.

Answer 7

Cohort : “A group of people who share a common characteristic or experience within a defined period”.

Question 8

Advantages of a Cohort Study

Answer 8

Temporality
Can calculate incidence
Useful for rare exposures
Can study multiple outcomes (of single exposure)

Question 9

Disadvantages of a Cohort study.

Answer 9

Loss-to-follow-up
Detection bias
Time consuming, expensive

Question 10

How is a cohort study conducted.

Answer 10

Get a sample population without the disease and then divide into groups that are exposed and not exposed and record outcomes.

Question 11

Compare Prospective and Retrospective studies.

Answer 11

Retrospective: Study begins when outcome has already occurred
Participants grouped on exposure (NOT outcome status)
Prospective: Outcome has not yet occurred
Participants grouped on basis of exposure
Follow up to see if outcome occurs

Question 12

Describe a case-control study.

Answer 12

Identify cases (those who have the outcome/disease)
Choose controls (those without outcome/disease)
Measure exposure in both cases and controls
Common sources  hospital, neighbourhood, family members. “Matched controls”

Question 13

Advantages of the case-control study

Answer 13

Efficient
Relatively quick
Good for rare outcomes

Question 14

Disadvantages of a Case control

Answer 14

Selection bias (selection of controls)
Information bias: Recall
Can only calculate odds ratio
No temporality

Question 15

How do we conduct a case control study?

Answer 15

From a population select Cases(Diseased) and Controls (No disease)- Controls need to represent the source population that gave rise to the disease. Thereafter divide each category into exposed and unexposed.

Question 16

Describe RC study.

Answer 16

Similar to cohort, but exposure
assigned randomly & always prospective

Question 17

Advantages of a RC study

Answer 17

Minimal bias/confounding-Participants have equal chance of receiving exposure/intervention as the control.
Strong evidence

Question 18

Disadvantages of a RC study

Answer 18

Ethical issues
Time-consuming, expensive
Loss-to-follow-up
Not suitable for all research questions

Question 19

Compare Blinding and Allocation concealment

Answer 19

Allocation concealment refers to the process of hiding or concealing the method used to assign treatments or interventions to participants in a research study. This ensures that neither the patients nor the clinicians/investigators know which treatment the participant will receive before they are enrolled in the study. The purpose of allocation concealment is to prevent bias in treatment assignment, ensuring that the groups being compared are comparable in terms of baseline characteristics.

Blinding, on the other hand, is a technique used to prevent bias in the assessment of outcomes during a study. It involves keeping the participants, healthcare providers, researchers, or outcome assessors unaware of the treatment group assignments. Blinding ensures that any differences observed in outcomes between treatment groups are not influenced by knowledge of the assigned treatment. There are different types of blinding, such as single-blind (where either the participant or the assessor is unaware of the treatment) and double-blind (where both the participant and the assessor are unaware).

Question 20

Describe Ecological studies.

Answer 20

Work with population or group-level variables. Previous examples were all looking at individual level. Study design itself can vary: but mostly cross-sectional ecological study

Question 21

Advantages of a Ecological study

Answer 21

Hypothesis generation
Relatively quick and cheap

Question 22

Disadvantages of an ecological study

Answer 22

Ecological fallacy – see next slide
Confounding, bias
Cannot determine causality

Question 23

Describe ecological fallacy.

Answer 23

The bias that may occur because an association observed between variables on an aggregate level does not necessarily represent the association that exists at an individual level” .
Ecological fallacy is the assumption that associations found at the group level apply to individuals

Question 24

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