Question 1. [12 marks] This question relates to the file diabet.sav. See the document “Description of datasets” on LMS for information on this dataset. Use SPSS (showing your output) and the file diabet.sav to produce requested output and answer the following questions.
a) [2 marks] Produce a scatterplot that shows the relationship between PDW and HAEM, obtain the correlation between PDW and HAEM, and then, using hand calculations, calculate a 95% confidence interval for the population correlation coefficient.
b) [4 marks] Fit a linear regression model of HAEM on PDW and using your output:
(i) [1 mark] Write down the fitted regression equation and provide an interpretation of the PDW coefficient.
(ii) [2 marks] Calculate the estimated difference in mean HAEM and its 95% confidence interval for subjects who have a PDW=120% vs subjects with a PDW=140%.
(iii) [1 mark] Using SPSS, calculate a 95% prediction interval for HAEM for an individual with PDW=122% and provide an interpretation of this interval.
c) [2 marks] Using SPSS, perform an appropriate test that compares the mean HAEM between the following two groups only: those treated for diabetes with insulin and those treated for diabetes with diet. From your output, state the estimated difference in mean HAEM for these groups and whether this difference is statistically significant and any assumptions you have made.
d) [1 mark] Provide an interpretation of the p-value from part (c) as a probability.
e) [3 marks] Using all data, create a dichotomous variable, DURGRP, which takes the value 1 if DURATION of diabetes is at least 10 years and the value 2 if DURATION of diabetes is less than 10 years. Create another dichotomous variable, TREATGRP, which takes the value 1 for those who are on treatment (TREAT) with insulin and the value 2 if they were being treated with either tablets or a diet. Label these variables appropriately and answer the following questions:
(i) [1 mark] Create a contingency table of TREATGRP by DURGRP.
(ii) [2 marks] By hand, calculate the odds ratio and 95% confidence interval of being on insulin, comparing those who have had diabetes for 10 or more years to those who have had diabetes less than 10 years. Based on this, is the length of time of having diabetes associated with the treatment they are on? Explain.
Question 2. [5 marks] A matched case-control study was carried out using data from the Australian Government Department of Veterans’ Affairs. 150 patients with post-operative delirium (the cases) and 150 patients without post-operative delirium (the controls) were selected from patients undergoing knee or hip surgery, giving 150 matched case-control pairs. The controls were 1:1 matched to the cases on age, sex, year of admission and socio-economic status. Use of medicines including sedatives, hypnotics, opioids and anti-depressants prior to surgery was compared between the cases and controls. There were 22 sets of case-control pairs who both had a history of medicine use, 47 sets of case-control pairs who both had no history of medicine use and 45 matched case control pairs where the case had a history of medicine use, but the control did not.
Use hand calculations and/or SPSS (showing output) to do the following:
a) [1 mark] Create an appropriate contingency table that displays the information provided in the question.
b) [2 marks] Obtain an estimate and 95% confidence interval for the odds ratio that compares the odds of post-operative delirium in patients who did and not have a history of medicine use. Write a sentence interpreting your estimate and confidence interval.
c) [1 mark] perform a test that compares the odds of post-operative delirium in patients who did and did not have a history of medicine use. What is your conclusion based on the p-value from this test?
d) [1 mark] Are your results in (b) and (c) compatible? Explain your answer.
Question 3. [3 marks] In late 2021, COVID-19 rapid antigen self-tests were approved in Australia. The TGA's performance requirements for COVID-19 rapid antigen self-tests are internationally aligned with technical specifications published by the World Health Organisation (WHO) and the European Commission. This includes a clinical sensitivity of at least 80% (for specimens collected within 7 days of symptom onset) and a clinical specificity of at least 98%. The Department of Health has reported on their website that the 2019-nCoV Ag Rapid Test Kit is the most accurate with a Sensitivity of 97% and a Specificity of 99%. Based on this information, using hand calculations, answer the following questions.
a) [1 mark] If a random sample of 1000 subjects with COVID-19 took the 2019-nCoV Ag Rapid Test, how many of them would you expect to test positive?
b) [1 mark] If a random sample of 1000 subjects without COVID-19 took the 2019-nCoV Ag Rapid Test, how many of them would expect to test positive
c) [1 mark] The Chief Health Officer has indicated that for these types of tests, from a public health perspective, it is more important to focus on the sensitivity of the test rather than the specificity of the test, and ensure sensitivity is as high as possible. In a single sentence suggest a reason why the Chief Health Officer would make this claim.
CS 340 Milestone One Guidelines and Rubric Overview: For this assignment, you will implement the fundamental operations of create, read, update,
Retail Transaction Programming Project Project Requirements: Develop a program to emulate a purchase transaction at a retail store. This
7COM1028 Secure Systems Programming Referral Coursework: Secure
Create a GUI program that:Accepts the following from a user:Item NameItem QuantityItem PriceAllows the user to create a file to store the sales receip
CS 340 Final Project Guidelines and Rubric Overview The final project will encompass developing a web service using a software stack and impleme
