Epidemiological Research Methods & Designs Part 2

Question 1

What are the categories of analytical studies ?

Answer 1

• Observational (e.g. Ecological studies , cohort ) : investigator does not have control over the exposure factor and is unable to assign subjects randomly
• Experimental (e.g. community intervention , clinical trial ) : Investigator controls who is exposed to a factor of interest and can assign subjects randomly to study groups

Question 2

Why may we use to ecological studies ?

Answer 2

• May be used when individual measurements are not available but group level data can be obtained

Question 3

Explain what a case-control study is ?

Answer 3

• its when we can analyze the study from the case aspect which would be comparing the cases as the disease exposed subject to we can analyze from the control aspect which would mean the no disease individuals are the exposed subject

Question 4

What is a matched case control study ?

Answer 4

• One in which the cases and controls have been matched according to one or more criteria

Question 5

What are some advantages and disadvantages of case-control studies ?

Answer 5

• Advantages : Can be used to study low prevalence conditions , quick and easy to complete , usually inexpensive , involve smaller number of subjects
• Disadvantages : Measurement of exposer may be inaccurate , number of cases and controls may be unknown , temporal relationship between exposure factor and outcome cannot always be determined

Question 6

What are the different types of cohort studies ?

Answer 6

• Perspective and retrospective cohort study

Question 7

What are the steps in conducting a cohort study ?

Answer 7

1. Define cohort
2. Invite subjects to participate
3. Obtain baseline exposure management
4. Follow cohort for disease
5. Analyze disease risk according to exposures

Question 8

What is the main difference between cohort and case control studies ?

Answer 8

• In cohort studies , we classify the study participants according to their exposure status (whether or not they have a particular risk factor)
• In case-control studies , we classify the study participants according to the health outcome of interest

Question 9

What are some advantages and disadvantages of cohort studies ?

Answer 9

• Advantages : Permit direct observation of risk , exposure factor is well defined , can study exposures that are uncommon in the population , temporal relationship between exposure factor and outcome is known
• Disadvantages: Expensive and time consuming , complicated and difficult to carry out , subjects may be lost to follow up during the course of the study

Question 10

What are the different types of experimental studies ?

Answer 10

• Randomized controlled trial
• Quasi experimental design

Question 11

What is a randomized controlled trial ?

Answer 11

• Subjects in a population are randomly allocated into two groups ,
  
  • Study group
  • control group
    then we compare the outcomes of interest

Question 12

What is a quasi experimental study ?

Answer 12

• A type of research in which the investigator manipulates the study factor but does not assign individuals subjects randomly to the exposed and non exposed groups

Question 13

What is a community intervention ?

Answer 13

• It is a intervention designed for the purpose of educational and behavioural changes at the population level

Question 14

What is the importance of analytical studies ?

Answer 14

• Lead to the prevention of disease
• Assist with the quantitative evaluation of intervention programs
• Aid in determining safety of new drugs and other products

Question 15

What is the definition of poverty ?

Answer 15

• Lack of resources , choices , opportunities and power to live fully in the community

Question 16

What are the three measures of poverty ?

Answer 16

• Low income cut off (LICO)
• Low income measures (LIM)
• Market basket measurements (MBM)

Question 17

What is low income cut off ?

Answer 17

• calculated by size of municipality and family size
• LICO is an income threshold below which a family will likely devote a large share of its income on the necessities of food , shelter and clothing than the average family

Question 18

What is Low income Measure ?

Answer 18

• a family is considered to be low income if they have less than 50% of the median adjusted household income

Question 19

What is Market based measure ?

Answer 19

• The costs of shelter , food m clothing , footwear , transportation , and other expenses , for a family go two adults and two children