1. Master of Public Health
Clinical Epidemiology and Chronic Disease Epidemiology For this assessment you are
required to read the information provided, research any terminology used or information
presented that you do not currently understand and then answer the following questions.
This assignment contains seven (7) questions and constitutes 75% of the module. A total of
100 marks are available for this assignment and the marks for each individual question are
clearly stated. Recommended time to complete the assignment is 5 hours (excluding
reading and research). Answer each question in about 100-300 words (depending on detail
of answer required), use Font size 11. Do not type outside the boxes provided. Do not cut
and paste. Question 1 (12 marks) Choose three diseases or conditions within a specific
setting (i.e. place or population group) of which you have some knowledge. Try to select
contrasting conditions, such as conditions affecting different age groups or of particular
importance in different parts of the world. Using the following matrix, for each condition
you have chosen, list the determinants under each of the six categories shown in the matrix.
Complete as many as seem appropriate. (four marks for each condition). 1 2 3 Disease or
condition Setting Determinants Age, sex, genes: Individual behaviours: Community and
social networks: Living and working conditions: Broader socio-economic and
environmental factors: Globally operating factors: Question 2 (18 marks) Select a chronic
disease of your choice and write short notes on its Epidemiology using the headings shown
below. (two marks for each part) 1. Public health significance 2. Patho-physiology 3.
Descriptive epidemiology 4. Causes 5. Prevention and control 6. Screening 7. Treatment 8.
Examples of evidence based interventions 9. Areas for future research Question 3 (13
marks) You are the head of an emergency department. Your department is seeing an
increasing number of patients who are HIV positive. After doing a preliminary cross-
sectional survey to assess the main types of sharps injury in the clinic, you realize that
needle stick injuries from blood drawing are frequent among nursing staff and that injuries
from suture needles are most frequent among doctors. You decide that you need to
implement a comprehensive programme of sharps injury prevention to protect your staff,
using Haddon’ s injury matrix as a guide to different countermeasures. Part A. Complete the
row and column headings for your Haddon matrix. (three marks) Part B. You persuade the
clinic administrator to purchase syringes with retractable needles to protect staff from
needle sticks during blood drawing. Place this action in the appropriate cell of the matrix
(two marks). Part C. In order to protect doctors from suture needle injuries, you introduce
mandatory teaching of essential safe surgical skills for all new doctors, including the use of
2. needle drivers and forceps to avoid touching of needles and wearing of latex gloves. Place
this action in the appropriate cell of the matrix (two marks). Part D. Think of two other
actions that you could take. Describe these actions and place them in the appropriate cell of
the matrix (four marks). Part E. There are two basic types of safety protection, the wearing
of latex gloves is which of these two types? (one mark) Part F. The epidemiological triad is a
main concept used in injury epidemiology. What is an agent in the needle-stick injury? (one
mark) Question 4 (13 marks) A study was made of doctors’ ability to diagnose
streptococcal infection in 149 patients coming to the emergency department with sore
throats. Doctors’ clinical impressions were compared to results of throat cultures for the
bacterium Group A streptococcus. Thirty-seven patients had positive throat cultures, and 27
of these were diagnosed by doctors as having strep throat. One hundred twelve patients had
negative cultures, and doctors diagnosed 35 of these as having strep throat. One mark for
Each Question 1. In this study what diagnostic test is being evaluated? 2. In this study what
is the Gold Standard? 3. What is the sensitivity of the doctors’ clinical impression of strep
throat in this study? 4. What is the specificity? 5. If the doctor thought the patient had strep
throat, for what percent of patients was she correct? 6. If the doctor thought the patient did
not have strep throat, for what percent of the patients was he correct? 7. How common was
strep throat in patients coming to the emergency department? 8. What is the Likelihood
Ratio of a positive test (ie. the doctor deciding on clinical grounds that a patient has strep
throat)? 9. Describe in your own words how you interpret this Likelihood Ratio 10. What is
the accuracy of the clinical impression of doctors about whether a patient has a strep
throat? 11. If the doctors knew results of the throat cultures when recording their clinical
impressions what effect would this have on the results of this study 12. If only some
patients attending the ER with sore throat got throat cultures, what effect would this have
on the results of this study. 13. Based on these findings, what advice would you give to the
ER doctors about taking throat cultures from patients with sore throat. Question Five (16
marks) Read the following abstract which summarises a prognostic study. There is limited
knowledge on prognostic factors for developing chronic low back pain (LBP) at an early
stage of LBP. The objectives of this study were to investigate the clinical course of pain and
disability, and prognostic factors for non-recovery after 1-year, in patients seeking help for
the first time due to acute LBP. An inception cohort study included 123 patients with acute
LBP lasting less than 3 weeks and consulting primary care for the first time. Main outcome
measures were pain intensity, Roland-Morris disability questionnaire (RMQ), and sickness
absence. Eleven patients (9%) did not return for the 12-month follow-up. There were large
and significant reductions in pain intensity (P<0.001) and RMQ scores (P<0.001) during
follow-up. Patients with neurological signs showed significantly less improvement in pain
(P=0.001) and RMQ (P=0.004) compared with those without neurological signs. The
proportions with sickness absence due to LBP at 6, 9, and 12 months were 7%, 8%, and 9%,
respectively. At 12 months, 17% of patients had not fully recovered. Multivariate logistic
regression analyses showed that high scores on a psychosocial screening (acute low back
pain screening questionnaire) and emotional distress (Hopkin’s symptom check list) were
significantly associated with non-recovery at 12 months, with odds ratios of 4.4 (95%
confidence interval 1.1-17.4) and 3.3 (1.1-10.2), respectively. Grotle M, Brox JI, Glomsrød B,
3. Lønn JH, Vøllestad NK. Prognostic factors in first-time care seekers due to acute low back
pain. Eur J Pain 2007; 11(3):290-8. Write 1-2 sentences on each of the following (two marks
for each section) 1. Was the sample of patients assembled in an appropriate way? 2. How
representative is the sample? 3. Was patient follow-up sufficiently long and complete? 4.
What were the outcome criteria, were these objective and applied in a ˜blind’ fashion? 5.
What different prognostic factors were identified and how did adjustment for these take
place? 6. What are the results? 7. How precise are the prognostic estimates? 8. Your brother
telephones to say that he has suddenly developed back-pain for the first time. Can you use
the results of this study to advise him? If so what will you say? Question 6 (Total of 15
Marks Available) Clinical Trials Please read the following extract from the Thompson et al.
(2010) article published in the Journal of Applied Physiology (108:769-779). Time course of
changes in inflammatory markers during a 6-mo exercise intervention in sedentary middle-
aged men: a randomized-controlled trial Study Background: ¢ Chronic low-grade
inflammation plays a central role in the aetiology of diseases such as cardiovascular disease
¢ Regular exercise may improve systemic markers of chronic inflammation, but direct
evidence and dose-response information is lacking ¢ Observational research provides
evidence for a strong inverse relationship between physical activity/fitness and serum
markers of inflammation (e.g. IL-6, CRP) ¢ Causal evidence from experimental studies
provides less consistent evidence as a number of short-term (1-3 months) and longer-term
exercise interventions (6-10 months) have shown either a positive impact or no impact on
markers of inflammation ¢ Limitations to these experimental studies include a lack of
control group, failure to assess compliance with the prescribed exercise intervention, and
poor measures of physical activity. Study Aim: The primary aim of the present randomised-
controlled trial was to examine the effect of a 6 month exercise intervention on the
magnitude and time course of changes in markers of low-grade inflammation in sedentary
middle-aged men. Materials and Methods: Participants. Sedentary male volunteers (aged
45“ 64 yr) were recruited from the local community. A total of 152 telephone screening
interviews were conducted (Fig. 1). Individuals with known disease (e.g., heart disease,
diabetes, arthritis) or who self-reported they engaged in structured physical activity lasting
=30 min on two or more occasions per week were excluded from the study, as were
volunteers who smoked, had a body mass index (BMI) =35 kg/m2, or took regular
medication. Eligible participants completed a health questionnaire and were fitted with a
physical activity monitor to further establish that they were sufficiently inactive, before
being randomly allocated to one of two groups using a sealed envelope (Fig. 1). The
envelopes were numbered with the sequence generated and known only by a third party.
Each volunteer provided written informed consent, and the investigation was approved by
the local ethics committee. Study design. Parallel group, randomised controlled trial.
Participants in both groups reported to the laboratory at baseline and then 4, 12, and 24
later, each time following a 12-h overnight fast. Exercise intervention and control.
Individuals in the exercise group completed a 24-wk exercise training program. Intensity
and duration were increased in a progressive manner. The exercise (attendance, exercise
duration, and heart rate) was recorded using a monitoring system (Fitronics, Bath, UK).
Once every fortnight, volunteers reported to the laboratory to complete one of their weekly
4. exercise sessions so that intensity and heart rate response could be monitored and the
exercise prescription altered accordingly. Men in the control group were asked to maintain
their current lifestyle and levels of physical activity during the 26-wk study period. Figure 1:
Flow of participants through the study Total of 15 marks available. 1. Figure 1 shows the
Flow of Participants through the study. One-hundred and fifty-two middle-aged men were
assessed for eligibility and 95 males were excluded from the allocation phase as they did
not satisfy the inclusion criteria. Using the data presented in Figure 1, calculate the
percentage of participants from the study population which formed the study sample. (1
mark) 2. State one possible reason why individuals on regular medication were excluded
from the study? (1 mark) 3. State the two screening methods used to ensure that all
participants in the study sample were classified as ˜ sufficiently inactive’ prior to group
randomisation (2 marks) 4. Define the term compliance and state which type of bias it is
related to? (2 marks) 5. Describe how the authors assessed compliance to the exercise
intervention (1 mark) During the Journal of Applied Physiology’s peer review process, one
of the reviewers suspects that the randomisation was not conducted blindly and that the
member of the study research team responsible for the group randomisation process
allocated the more physically inactive (i.e. sedentary) middle-aged males preferentially to
the treatment (exercise intervention) group. 6. What is the gold standard method of group
randomisation in a randomised-controlled trial? (1 mark) 7. State one reason why using a
non-random group allocation procedure might distort the ˜true’ effect of the exercise
intervention? (1 mark) 8. Which type of bias is associated with a failure to randomise
participants? (1 mark) 9. Which statistical test could the study researchers perform to
provide evidence that group allocation was random? (1 mark) 10. What does the term
blinding mean? (1 mark) 11. Why was it not possible to blind study participants to group
allocation? (1 mark) 12. Using the data presented in Figure 1, state the total number of
participants that would be involved in the following analyses: (i) Intention to treat analysis
(1 mark) = (ii) Per-protocol analysis (1 mark) = Question 7 (Total of 13 Marks Available)
Systematic Reviews and Meta-Analysis Please read the following abstract from a systematic
review and meta-analysis conducted by Umpierre and colleagues which was published in
the Journal of the American Medical Association. 2011;305(17):1790-1799): Abstract
Physical activity advice only or structured exercise training and association with HbA1c
levels in type 2 diabetes. A systematic review and meta-analysis Note: Glycated hemoglobin
(HbA1c) is a blood marker used to monitor blood glucose levels. Higher amounts of HbA1c
indicate poorer control of blood glucose and have been associated with cardiovascular
disease in type 2 diabetes patients. The American Diabetes Association Standards of Medical
Care in Diabetes 2011 guidelines state HbA1c =6.5% the criterion for the diagnosis of
diabetes. Context: Regular exercise improves glucose control in diabetes, but the association
of different exercise training interventions on glucose control is unclear. Objective: To
conduct a systematic review and meta-analysis of randomized controlled clinical trials
(RCTs) assessing associations of structured exercise training regimens (aerobic, resistance,
or both) and physical activity advice with or without dietary co-intervention on change in
hemoglobin A1c (HbA1c) in type 2 diabetes patients. Data Sources: MEDLINE, Cochrane-
CENTRAL, EMBASE, ClinicalTrials.gov, LILACS, and SPORTDiscus databases were searched
5. from January 1980 through February 2011. Study Selection: RCTs of at least 12 weeks’
duration that evaluated the ability of structured exercise training or physical activity advice
to lower HbA1c levels as compared with a control group in patients with type 2 diabetes.
Data Extraction: Two independent reviewers extracted data and assessed quality of the
included studies. Data Synthesis: Of 4191 articles retrieved, 47 RCTs (8538 patients) were
included. Pooled mean differences in HbA1c levels between intervention and control groups
were calculated using a random-effects model. Overall, structured exercise training (23
studies) was associated with a decline in HbA1c level (-0.67%; 95% confidence interval [CI],
-0.84% to -0.49%; I2, 91.3%) compared with control participants. In addition, structured
aerobic exercise (-0.73%; 95% CI, -1.06% to -0.40%; I2, 92.8%), structured resistance
training (-0.57%; 95% CI, -1.14% to -0.01%; I2, 92.5%), and both combined (-0.51%; 95%
CI, -0.79% to -0.23%; I2, 67.5%) were each associated with declines in HbA1C levels
compared with control participants. Structured exercise durations of more than 150
minutes per week were associated with HbA1c reductions of 0.89%, while structured
exercise durations of 150 minutes or less per week were associated with HbA1C reductions
of 0.36%. Overall, interventions of physical activity advice (24 studies) were associated
with lower HbA1c levels (-0.43%; 95% CI, -0.59% to -0.28%; I2, 62.9%) compared with
control participants. Combined physical activity advice and dietary advice was associated
with decreased HbA1c (-0.58%; 95% CI, -0.74% to -0.43%; I2, 57.5%) as compared with
control participants. Physical activity advice alone was not associated with HbA1c changes.
Conclusions: Structured exercise training that consists of aerobic exercise, resistance
training, or both combined is associated with HbA1c reduction in patients with type 2
diabetes. Structured exercise training of more than 150 minutes per week is associated with
greater HbA1c declines than that of 150 minutes or less per week. Physical activity advice is
associated with lower HbA1c, but only when combined with dietary advice. Total of 14
marks available. 13. Read the abstract and state two inclusion criteria for studies to be
selected for the systematic review (2 marks). i. ii. 14. During the ˜Data Extraction’ phase of
the study two independent reviewers extracted data and assessed quality of the included
studies. Why? (1 mark) 15. Name two potential sources of bias related to the literature
search (2 marks) i. ii. 16. State one strength and one limitation of a meta-analysis? (1 mark)
Strength: Limitation: 17. Which test can be used to determine the presence of heterogeneity
in a meta-analysis? (1 mark) 18. In the ˜Data Synthesis’ section of the abstract the authors
state that œpooled mean differences in HbA1c levels between intervention and control
groups were calculated using a random-effects model.• What is the main assumption of a
random effects model? (1 mark) 19. The authors provide details of which databases were
used during the literature search to find published articles. Name one method of obtaining
unpublished literature. (1 mark) 20. Which type of graph can be used to assess publication
bias in a meta-analysis? (1 mark) 21. Look at the Forest Plot displayed in Figure 1 (below).
Three studies (Raz et al., 1994; Vancea et al., 2009c; Vancea et al., 2009d) appear to have
wide confidence intervals which cross the line of unity, what does that suggest about the
results of those individual studies? (1 mark) 22. Based on the results in the ˜Data Synthesis’
section of the abstract and the Forest plot presented in Figure 1 (below), which type of
exercise training (i.e. aerobic, resistance, or combined aerobic and resistance training) and
6. duration (minutes per week) would you prescribe to a diabetes patient looking to maximise
the beneficial effects of exercise training on HbA1c? (2 marks) Type of Exercise Training:
Weekly Duration of Exercise Training (minutes per week): 45 MLS recording system ¢ ¢?
During the workshops you will be participating in scenarios as the attending paramedic.
These will be recorded using the MLS recording system. You will be able to log-in and view
your own scenarios to evaluate and reflect on the case and the way you approached your
decision making (linked to Module 4 professionalism and evidence based practice). ¢ ¢?
Below is a template to assist you in formulating your analysis of your scenario. Criteria
Strengths What you did well? The student demonstrates the ability to identify the aspects of
their practice they performed well. Support your actions and why they are appropriate
clinical practice. The student provides evidence (links to literature) why they considered
their actions good practice and rationale for their clinical decisions. Weaknesses What you
could have done better? The student demonstrates the ability to identify the aspects of their
practice they could improve. Support why you consider the areas you identified require
improvement The student provides evidence (links to literature) why they considered the
areas of practice and clinical decisions need improvement. Opportunities What could you
research and learn more about? The student identifies areas of learning and ways to meet
those learning needs and relates these to improved clinical decision making. Threats What
was difficult about the scenario and why? The student identifies areas that they found
difficult and supports why they found them difficult. The strengths and weakness need to be
an in-depth discussion about what you did well and why and where you felt you could have
improved in your clinical decision making (linked to literature “ supported by evidence).
The strategies for improvement, the learning opportunities, need to be referenced to
literature. The difficult aspects of the scenario need to be supported with discussion about
why they were found difficult. ¢?Note that class sizes dictate that you will not always have
the opportunity each week to play the role of attending paramedic. You should make sure
that you do participate as often as possible. PARA 3002 Decision Making in Paramedic
Practice: Reflective Assignment Student Name: GRADE: / 50 Criteria Mark Grade Comment
1. Strengths What you did well? ¢ ¢? Demonstrates the ability to identify the aspects of their
practice they performed well. ¢ ¢? Areas of practice are identified with reference to at least
three (3) of the following areas: o “ Knowledge of pathophysiology o “ Knowledge of
treatment pathways and o “ the ramifications of treatment in complex patient
presentations o “ Knowledge of scene management o “ Knowledge of resources o “
Knowledge of social and psychological aspects of patient presentations 5 2. Support your
actions and why they are appropriate clinical practice. ¢ ¢? The student provides evidence
(links to literature) why they considered their actions good practice and rationale for their
clinical decisions. ¢ ¢? Evidence of at least three (3) aspects of practice that they have
supported from literature. ¢ ¢? A clear rationale is provided for the decisions made and why
they have been identified. ¢ ¢? Evidence of links to the case scenario ¢ ¢? (at least four (4)
references provided to support clinical decision making) 10 3. Weaknesses What you could
have done better? ¢ ¢? The student demonstrates the ability to identify the aspects of their
practice they could improve. ¢ ¢? Areas of practice are identified with reference to at least
three (3) of the following areas: o “ Knowledge of pathophysiology o “ Knowledge of
7. treatment pathways and o “ the ramifications of treatment in complex patient
presentations o “ Knowledge of scene management o “ Knowledge of resources o “
Knowledge of social and psychological aspects of patient presentations 5 4. Support why
you consider the areas you identified require improvement ¢ ¢? The student provides
evidence (links to literature) why they considered the areas of practice and clinical
decisions need improvement. ¢ ¢? Evidence of at least three (3) aspects of practice which
have been identified and supported from literature. ¢ ¢? A clear rationale is provided for the
decisions made and why they have been identified for improvement. ¢ ¢? Evidence of links
to the case scenario ¢ ¢? (at least four (4) references provided to support why these areas of
clinical decision making are important for improvement) 10 5. Opportunities What could
you research and learn more about? ¢ ¢? The student identifies areas of learning and ways
to meet those learning needs and relates these to improved clinical decision making. ¢ ¢?
Strategies are discussed to how the identified learning needs can be met. ¢ ¢? Links to at
least two (2) pieces of peer reviewed literature to support the strategies discussed 10 6.
Threats What was difficult about the scenario and why? ¢ ¢? Barriers or challenges are
identified to the clinical decisions made in the case ¢ ¢? Rationale’s are provided for the
identified barriers and challenges ¢ ¢? Evidence of links to the case 10
