University of Western Sydney Introduction to Epidemiology Assignment 1

This document presents a solved assignment for an Introduction to Epidemiology course at the University of Western Sydney. The assignment covers key epidemiological concepts, including calculating prevalence, incidence, and crude rates. It involves analyzing data to determine disease frequency and comparing rates between different populations. The solution addresses various study designs, such as cross-sectional and cohort studies, and explains their applications. Furthermore, it includes an analysis of a randomized controlled trial (RCT) and discusses its advantages. The assignment also explores factors related to health outcomes, such as respiratory symptoms and falls in the elderly. The solution provides detailed answers to each question, demonstrating the application of epidemiological principles and methodologies.

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The University of Western Sydney
School of Science and Health
Introduction to Epidemiology (401076)
ASSIGNMENT 1
Autumn, 2019
Due date: 7/04/2019 midnight

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Question 1
(a) Answer: (Number of diabetic (1st, 2016)/population) x100
(3600/73000) x100= 4.93%
(b) Answer ((3600+230)/73,000) x100= 5.35%
(c) Answer: (Number of new cases/population at start) x100
(230/730000) x100= 0.31%
(d)
Secondary attack rate
New cases/ (remaining population after death) x100
(230/ (73000-5000)) x 100= 0.34%
Question 2:
a)
(Death from all causes in NSW/ total population) x1000
(49,607/9 006043) x1000= 5.508 per 1000 people
(b)
(Deaths from type 2 disease related causes/total population) x 1000
(5025/9006043) x 1000
0.558 Per 1000 people
(c)
Answer= (Deaths from type 2 diabetes related causes /number of people with
type 2 diabetes) x 100
= (5025/756507) x 100=0.66%
Question 3:

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(a)
City A: Total women population 400,000+175, 000+125000= 700,000
Number of breast cancer= 50+250+350=650
Crude rates= (number breast cancer/women population) x 100,000 = 92.8 per 100,000
people
City B; Total population= 400,000+ 100,000+ 10,000= 510,000
Number of breast cancers= 30+100+500= 630
(630/510,000) x100000=123.5 per 100,000 people
There are more crude rates in B than in A.
(b)
City A
20-44= (50/40000)*100,000=12.5 per 100000 people
45-64= (250/175000)*100000=142.9 per 100000 people
65+= (350/125000)* 100,000= 280 per 100,000 people
City B:
20-44= (30/40000)*100,000= 75 per 100000 people
45-64= (100/100000)*100000=100 per 100000 people
65+= (500/10000)* 100,000=5000 per 100000 people
In the two cities, more deaths were in old ages, 65+
(c)
City A: (630/100000) x 100= 0.63%
City B: (650/100000) x 100= 0.65%

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City A has less incidence rate than city B.
d)
Yes. It is important since it gives one value against which the two cities are compared
to clearly see the differences.
Question 4
The number of people with a disease within the community increases when
a. Incidence rate < death rate + cure rate
b. Incidence rate < prevalence rate < death rate + cure rate
c. Prevalence rate = death rate + cure rate
d. Incidence rate > death rate + cure rate
Question 5:
a)
What is the prevalence of respiratory symptoms due smoking across the age and sex?
b)
Cross-sectional
c)
Takes place at a one point in time and does not involve any manipulating variables
and also allows researchers to look at various characteristics like age and sex at once
Question 6:
a)
What are the factors leading to falls of the elderly?
b)
Prospective cohort study: It is a design that follows over time cohorts of
people who are similar in various ways but vary by some features to compare

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the cohort for a specific outcome (Truxal et al., 2016). This is a prospective
study because at the beginning of the enrolment of subjects, and colleting
baseline exposure information, no subjects has already developed any interest
of outcome
c)
How frequently do you engage in physical activity per week? This question
will also help gather the information from these people to understand whether
their frequency of falls is due to lack of exercise.
Question 7:
a)
Randomized Controlled Trial
b)
Control group
Treated group
c)
The advantage of RCT is that it reduce selection bias (Ang et al., 2015).
d)
Hypothesis: Eating raw clams or oyster leads to infectious hepatitis

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References
Ang, K. K., Chua, K. S. G., Phua, K. S., Wang, C., Chin, Z. Y., Kuah, C. W. K., ... &
Guan, C. (2015). A randomized controlled trial of EEG-based motor imagery
brain-computer interface robotic rehabilitation for stroke. Clinical EEG and
neuroscience, 46(4), 310-320.
Truxal, K. V., Fu, H., McCarty, D. M., McNally, K. A., Kunkler, K. L., Zumberge, N.
A., ... & Lowes, L. P. (2016). A prospective one-year natural history study of
mucopolysaccharidosis types IIIA and IIIB: Implications for clinical trial
design. Molecular genetics and metabolism, 119(3), 239-248.