Assessment 3: Public Health Data Analysis
The slogan for World Health Day 2004 – Road Safety Is No Accident – suggests that road safety does not happen accidentally, but requires a deliberate effort by governments and their many partners.
The WHO strategy for road traffic injury prevention has three objectives:
In Australia, on average, five peoples die every day in road crashes. In a 2018 report by the ABC using national data found that:
According to the AIHW Injury in Australia: transport accidents report (updated 9 Dec 2021), in 2018-19, transport injuries resulted in:
This is despite Australia’s strong legislative approach to road safety. Public health experts know:
Links:
The Council of Roberton is interested in investigating risk factors that can lead to road accidents in their population. They have sent out a tender for the brightest researchers to inform their future public health policies and health promotion interventions. They are interested in the association between physical activity in terms of reaction time for stopping a car and preventing an accident.
The good news is that they have existing historical data. The data was collected from a census index from the Council of Roberton which has 17,935 residents aged between 6 years to 80 years. Each individual’s data were identified by a six-letter identification code. From the records given on Moodle in the Excel file “Roberton Dataset.xlsx”, the age group and gender of each person in this population are known. Gender was only collected as a binary variable: Male and Female. This data is a snapshot in time and there is no historical or post-research data available.
The Council wanted to examine the association between reaction time and physical activity. Therefore, they have conducted a one-off test as part of their health assessments and collected the reaction time of the individuals. A quick reaction time on the test is considered an indicator of a good ability when to stop a car.
A stratified random sample of 100 Roberton residents has been obtained. The stratification was based on the age groups and the sample size from each stratum was in proportion to that in the population:
Age Group | 6-20 | 21-35 | 36-50 | 51-65 | 65-80 |
% | 22 | 23 | 25 | 19 | 11 |
Variable | Descriptor |
Age | Years (recorded as the date of birth) |
Gender | Male (M) and Female (F) |
Handedness | Left-Handed (LH) and Right Handed (RH) |
Physical activity | Hours per week |
Reaction time to test | Seconds |
Reaction time: Slow and Quick | Slow (>= 0.31 sec) & Quick (<0.31 sec) |
DATASET:
Volunteer | ID | Age | Gender | Handedness | Phys. Act. | Reac. Time | Reacton time: slow vs quick |
1 | IHVDDL | 26 | M | RH | 3.5 | 0.254074 | Quick |
2 | NCMEOX | 43 | F | RH | 1.5 | 0.390774 | Slow |
3 | SBRHPO | 44 | M | RH | 4 | 0.300103 | Quick |
4 | LVCZRF | 64 | M | RH | 3 | 0.415153 | Slow |
5 | XTVSFC | 20 | M | RH | 4.5 | 0.250908 | Quick |
6 | XDRZKO | 28 | F | RH | 3 | 0.328946 | Slow |
7 | MBNMJB | 58 | F | RH | 3.5 | 0.327346 | Slow |
8 | CUOMNB | 52 | F | RH | 3.5 | 0.323848 | Slow |
9 | OZHARU | 19 | M | RH | 6 | 0.250345 | Quick |
10 | DEKZIA | 51 | F | RH | 3 | 0.364936 | Slow |
11 | SGBVTW | 43 | M | LH | 4 | 0.263651 | Quick |
12 | ZEMJFK | 43 | F | RH | 3 | 0.349891 | Slow |
13 | QKAZUL | 35 | M | LH | 5 | 0.226787 | Quick |
14 | VNJVGG | 19 | M | RH | 5 | 0.202515 | Quick |
15 | CSRNFW | 44 | M | RH | 4 | 0.322696 | Slow |
16 | IEFZGB | 15 | F | RH | 4 | 0.294385 | Quick |
17 | LZSUZN | 14 | M | LH | 4 | 0.201525 | Quick |
18 | WUQKQT | 10 | F | RH | 4 | 0.276566 | Quick |
19 | PNEKWX | 28 | M | RH | 3 | 0.273305 | Quick |
20 | TUWUIB | 52 | M | RH | 2 | 0.335039 | Slow |
21 | HTYTIZ | 74 | M | RH | 2 | 0.406903 | Slow |
22 | CQBIEK | 30 | F | RH | 4 | 0.308271 | Quick |
23 | NTTIWH | 80 | F | RH | 3 | 0.408785 | Slow |
24 | MBEVBF | 9 | M | RH | 5.5 | 0.228226 | Quick |
25 | SXFIOZ | 19 | F | RH | 3.5 | 0.235167 | Quick |
26 | MMDHJO | 40 | F | RH | 2 | 0.373712 | Slow |
27 | XTJTWD | 32 | M | RH | 5 | 0.236355 | Quick |
28 | MQKEOV | 41 | F | RH | 3 | 0.330303 | Slow |
29 | MOULBE | 38 | M | RH | 3 | 0.342959 | Slow |
30 | AVQKZS | 14 | M | RH | 5 | 0.227944 | Quick |
31 | FFLNML | 64 | F | RH | 3 | 0.402127 | Slow |
32 | DIGFUL | 29 | F | LH | 3.5 | 0.245797 | Quick |
33 | YTNIEZ | 47 | F | RH | 1.5 | 0.336358 | Slow |
34 | SFKMGD | 11 | F | RH | 4 | 0.215319 | Quick |
35 | HEUUNJ | 63 | M | RH | 2.5 | 0.34338 | Slow |
36 | NEGDOQ | 34 | F | RH | 3.5 | 0.265359 | Quick |
37 | BSVYMI | 9 | M | RH | 4.5 | 0.233361 | Quick |
38 | IJFHLS | 58 | M | RH | 1.5 | 0.349041 | Slow |
39 | FESBNT | 47 | M | RH | 2.5 | 0.3884 | Slow |
40 | CNHEMA | 65 | M | RH | 2 | 0.430545 | Slow |
41 | CWZNLS | 39 | M | RH | 2 | 0.354201 | Slow |
42 | QPMVUT | 38 | M | RH | 3.5 | 0.296223 | Quick |
43 | PTJFWW | 56 | F | RH | 2.5 | 0.411136 | Slow |
44 | LLZBOA | 58 | M | RH | 2 | 0.415038 | Slow |
45 | GJUVFI | 43 | M | RH | 3 | 0.324668 | Slow |
46 | QYBTNW | 45 | F | RH | 1.5 | 0.345047 | Slow |
47 | AAIRSA | 27 | F | RH | 3 | 0.289131 | Quick |
48 | JQEXEC | 17 | M | RH | 4.5 | 0.204639 | Quick |
49 | FRBPQZ | 63 | F | RH | 1 | 0.451813 | Slow |
50 | XTWNSJ | 13 | M | RH | 6 | 0.209233 | Quick |
51 | SONPZC | 36 | M | RH | 2.5 | 0.289609 | Quick |
52 | IQNVAC | 33 | M | RH | 5 | 0.256971 | Quick |
53 | MPOSOE | 48 | M | RH | 4 | 0.343136 | Slow |
54 | GBHCDK | 14 | M | RH | 5.5 | 0.183928 | Quick |
55 | UELXCD | 52 | F | RH | 2 | 0.397813 | Slow |
56 | RAFLUQ | 40 | F | RH | 1.5 | 0.319358 | Slow |
57 | MBJXYS | 48 | F | RH | 1.5 | 0.351163 | Slow |
58 | UNMRHO | 14 | M | RH | 6 | 0.202551 | Quick |
59 | PMYSPL | 15 | F | RH | 5 | 0.197103 | Quick |
60 | ILJJMK | 48 | M | RH | 3 | 0.375297 | Slow |
61 | QZROYJ | 65 | F | RH | 3.5 | 0.371229 | Slow |
62 | VYJVHD | 35 | M | RH | 5 | 0.318889 | Slow |
63 | QFUBQK | 13 | M | RH | 6 | 0.196339 | Quick |
64 | LJOQYQ | 69 | F | LH | 0.5 | 0.378272 | Slow |
65 | GMSRCA | 73 | M | LH | 1.5 | 0.368826 | Slow |
66 | OMKDVR | 37 | F | RH | 2.5 | 0.366972 | Slow |
67 | EBTOIJ | 52 | M | RH | 1.5 | 0.42042 | Slow |
68 | TSUJEB | 50 | M | RH | 2.5 | 0.36039 | Slow |
69 | IKAMON | 9 | F | RH | 5.5 | 0.176372 | Quick |
70 | EMXRID | 62 | F | RH | 2.5 | 0.41135 | Slow |
71 | OIXEFY | 67 | F | RH | 1 | 0.385949 | Slow |
72 | ZPFUEX | 11 | F | RH | 3 | 0.294913 | Quick |
73 | CFQFDJ | 6 | F | LH | 3.5 | 0.193657 | Quick |
74 | QAJNNV | 7 | F | RH | 5 | 0.246434 | Quick |
75 | ZPCLMA | 27 | F | RH | 3.5 | 0.316907 | Slow |
76 | APWZDY | 24 | M | LH | 5 | 0.203713 | Quick |
77 | KTDTFB | 75 | M | RH | 2 | 0.456536 | Slow |
78 | GAAWQB | 9 | M | LH | 4.5 | 0.187153 | Quick |
79 | DQYYAW | 18 | M | RH | 4.5 | 0.268085 | Quick |
80 | CZOKCZ | 66 | M | RH | 0.5 | 0.411091 | Slow |
81 | YLBHXJ | 8 | M | RH | 6 | 0.16851 | Quick |
82 | EIOHUL | 9 | F | RH | 3 | 0.26532 | Quick |
83 | ZKUZLC | 14 | F | RH | 4 | 0.212277 | Quick |
84 | ASQWBJ | 71 | M | RH | 0.5 | 0.415695 | Slow |
85 | STPQKA | 43 | F | RH | 3 | 0.368288 | Slow |
86 | JSPACY | 31 | F | RH | 2.5 | 0.278953 | Quick |
87 | SLZNQC | 12 | F | RH | 3.5 | 0.222009 | Quick |
88 | PRYMNW | 55 | F | RH | 2 | 0.365204 | Slow |
89 | TIGFWA | 32 | M | RH | 5.5 | 0.229825 | Quick |
90 | HFXUKA | 43 | F | RH | 2 | 0.381614 | Slow |
91 | ZRBLZF | 47 | M | RH | 4 | 0.292199 | Quick |
92 | DDOIWB | 34 | F | LH | 3 | 0.260509 | Quick |
93 | EUJKGH | 51 | F | RH | 1 | 0.362534 | Slow |
94 | KFWAMH | 12 | F | RH | 4.5 | 0.229808 | Quick |
95 | VTRWSR | 11 | F | RH | 3 | 0.246107 | Quick |
96 | PFAGGU | 32 | M | LH | 5 | 0.21584 | Quick |
97 | LDTOBG | 25 | M | RH | 5 | 0.243748 | Quick |
98 | KQDGMK | 34 | M | RH | 5.5 | 0.233727 | Quick |
99 | SQLZZA | 42 | M | RH | 2.5 | 0.30988 | Quick |
100 | RXQQHR | 72 | F | RH | 3 | 0.43385 | Slow |
The Council of Roberton is really concerned about the number of recent road accidents, and has called a community meeting. They have called for an enquiry named the Roberton report. You are part of the team to help them make decisions for their community. The aim of your assignment is to investigate injury prevention and road safety.
Let’s ask some preliminary questions about accidents.
Additional resources:
List 2 direct factors and 2 upstream factors. (4 marks)
Using the graph provided, state the distance travelled in meters if the car is travelling at 60 km/hr on a dry road. (no units required) (1 mark)
Describe your findings of whether the car stopped at 60 km/hr or 100 km/hr for the child 45 m away by completing these two sentences:
o At 60 km/hr, the car will … o At 100 km/hr, the car will … (2 marks)
It is important to have an understanding of your data and variables in research.
Before we start our analysis, we need to understand our population and the sampling methods used. Then, before we do any statistical tests, we need to describe the data with descriptive statistics and graphs.
Resources: Please see the “Useful Assessment Resources” folder for a PDF of the questions in the quiz, as well as the “Formula Sheet & Tables” document.
What had to be known to achieve it? (Select 1 or more correct answers) [3 marks]
Variable | Descriptors | Type of Data |
Age | Years (recorded as the date of birth) | |
Gender | Male (M) and Female (F) | |
Handedness | Left Handed (LH) and Right Handed (RH) | |
Physical activity | Hours per week | |
Reaction time | Seconds | |
Reaction time: Slow and Quick | Slow (>= 0.31 sec) & Quick (<0.31 sec) |
Therefore your next step is to:
Draw a graph of reaction time.
Please attach the graph as a file below.
In the text box, type the file name only. [5 marks]
Answers to FAQ for this question:
What is the mean of the sample? (4 decimal places) [1 mark]
“The graph shows a fairly normal distribution, and the values of the mean & median are fairly similar.
Hence, the mean is an appropriate statistic to describe reaction time.” [0.5 mark]
What is the reaction time range of your sample? (4 decimal places) [1 mark]
Let’s have a closer look at some key variables: Gender and Reaction time: slow vs quick.
To answer this section, you’ll need to create a summary table that shows the frequency and percentages.
You’ll also need to create an appropriate graph & interpret your results.
Slow n (%) | Quick n (%) | Total n (%) | |
Male | |||
Female | |||
Total |
Questions 15 to 19 below are (1 decimal place, no units required) format.
After creating your graph select the graph below which best represents your data. [1 mark]
How could you improve the graph in the question above? (Select all that apply) [3 marks]
Great news, the Council of Roberton has found your preliminary results very valuable.
Now let’s do some statistical tests to investigate the data in more detail.
The first thing we’ll be looking at is: Do males and females differ in their reaction times?
Over the next few questions you will need to create a summary table and conduct a test of significance (95% CI and p-value) between the males and females to answer if there is a difference between their reaction times. Follow all steps clearly and write a clear conclusion.
Hint: Let’s complete all the steps in hypothesis testing.
Distribution of data in each group:
Groups being compared are:
Patients within each group are:
Equality of group variance using Levenes (ratio) test:
Congratulations. You’ve now got the necessary statistics to calculate the p-value and 95%CI
“As the p-value is > 0.05, the p-value is not significant. Therefore, in this sample we can not justify rejecting the null hypothesis.”
Hint: Write your answer as x.xxx to y.yyy, e.g. -0.123 to 1.234
Now, let’s look at the relationship between handedness and reaction time: slow vs quick.
Hint: For this question, you’ll need your data summarised in the table below.
Slow | Quick | Total | |
Left | |||
Right | |||
Total |
Next, you will calculate the SE and 95% CI of the Odds Ratio, and interpret the 95% CI.
You will need your odds ratio (handedness (left) and reaction time (slow)) from the earlier question to 6 decimal places.
This interval <A> the value of <B>, so it <C> statistically significant
A: includes; excludes
B: 0; 1
C: is; is not
As the p-value is <A> than 0.05, the null hypothesis is <B>.
The odds of having a slow reaction time is <C> left and right handed people.
A: greater than ; less than
B: not rejected ; rejected
C: the same among ; different between
(Section F follows on the next page…)
The Council of Roberton has contacted you and is really interested in the association between physical activity and how this impacts on your reaction time in the test.
Is there a correlation between the physical activity reported and their reaction times? You are going to need to justify your answer using appropriate graphs, interpreting correlation coefficients and appropriate summary conclusions.
Please attach the graph as a file below.
In the text box, type the file name only. [5 marks]
“Overall, there was a [X] correlation between reaction times and physical activity. [Y] in physical activity were correlated with [Z] reaction times of individuals.”
Congratulations! This is the end of your investigation.
Now it is time to finalise those conclusions and submit your recommendations to the Council.
Key points required: