HEAPH6003 Analyse the association between heart disease and the following variables using an appropriate statistical test–

Required Data: Smoking data and Heart_Disease -Data (see the Assignment Task 3 Section on Moodle)

Exercise 1 [3 marks]: Let us consider an example where the body mass index (BMI) of the cardiac surgery patients in a population follows a normal distribution with true mean (m) of 27.94kg/m2 and true standard deviation (SD) of 4.85 kg/m2.

Fill up the following gaps:

  1. 68% of patients have BMI between _ and (i.e., probability that the BMI of a randomly selected patient lies between and is 68%).
  2. 95% of patients have BMI between and (i.e., probability that the BMI of a randomly selected patient lies between and is 95%).
  3. 99.7% of patients have BMI between and _ (i.e., probability that the BMI of a randomly selected patient lies between and is 99.7%).

Exercise 2 [2 marks]: Consider the weight of adult Australians in a large sample follows a normal distribution with mean 78kg and standard deviation 10kg.

  1. What is the median weight for the adult Australians?
  2. Find the limits that include 99.7% of adult Australians

Exercise 3 [3 marks]The length of human pregnancies from conception to birth varies according to a distribution that is approximately normal with mean 266 days and standard deviation 16 days.

Use the normal distribution concept to answer the following questions –

  1. Between what values do the lengths of the middle 95% of the pregnancies fall?
  2. How short are the shortest 2.5% of all pregnancies?
  3. How long are the longest 2.5% of all pregnancies.

Exercise 4: Data description [12 Marks]

Consider a study where few variables (e.g., age, gender, BMI, comorbidities, heart disease etc.) were collected from 350 participants. The objective of the study was to investigate whether heart disease is related to these variables.

Tasks:

  1. Identify dependant and independent variables of this study from the given dataset [2 marks]
  2. Analyse the association between heart disease and the following variables using an appropriate statistical test–
  • Sex
  • proposed waist circumference
  • Diabetes
  • Chronic respiratory disease
  • High blood pressure
  • Proposed nutrition level
  • Proposed BMI
  • Tobacco Use
  • Betel leaf use

Summarise the important results of your analysis in a table in the test and discuss strength of association [Hints: p value, ORs, CIs, and %) [4marks]

  1. Calculate the following descriptive statistics using Body Mass Index variable and summarise your results in a table and discuss-
  • Range
  • Minimum
  • Maximum
  • Mean
  • Standard deviation
  • Skewness and Kurtosis
  • Generate histogram with normal curve and box plot [4marks]
  1. Present the distribution of the occupation data of the participants in a pie chart and add a title and label on the chart with percentages and discuss your result. [2marks]

Exercise 5: Consider a hypothetical study was conducted among 209 participants to examine the level of nicotine (pre and post) among smokers (social, past and current) before and after smoking. In this example, consider smoking as an intervention. [16 marks]

Tasks

  1. Compare the means of nicotine level among the participant smokers (social, past and current) before smoking. Then, compare the means of nicotine level among the participants (social, past and current) after smoking. Discuss and present your analysis in table and text using an appropriate statistical test [8 marks]
  2. Using an appropriate statistical test, compare nicotine levels of all participants before and after the intervention (smoking) and explain if there is any effect of smoking on the mean scores for pre and post nicotine levels. [8 marks]

Hints: compare of means in groups, parametric test, P-value, CIs

Overall presentation: Tables, interpretation, graphs, correct grammar and spelling, formatting etc No restriction on word count, but it is expected that your assignment to be succinct [4marks].