401077 Introduction to Biostatistics, Spring 2017
Assignment 3
(Due Sunday October 22, 2017)
Please answer each question in the template document provided and submit via Turnitin on or before the due date. The marks allocated to each question are shown in the assignment. A total of 40 marks are available and this assignment is worth 40% of your overall grade.
One of the questions in this assignment ask you to analyse the data set assigned to you for assignments. This is the same data set which you used for Assignments 1 and 2. Read ‘Description of your data set.docx’ for the descriptions of the variables.
This assignment is assessing your skills, not the skills of the computer. You will need to include graphs from R Commander into your assignment but all other R Commander output will attract 0 marks and is discouraged. It is your task to identify the relevant results in the R Commander output and write these up in your assignment.
Question 1 (18 marks)
Read the paper Deere K, Williams C, Leary S, et al (2009). Myopia and later physical activity in adolescence: a prospective study. British Journal of Sports Medicine, 43,542–544.
Critically appraise of the statistical material in this paper against items 10, 12-17 of the STROBE checklist. Present your review as a 400-500 word (approx.) report.
Notes:
- Only review the provided paper Deere et al, 2009. Do not read any other papers.
- Restrict your review to how well Deere et al have documented their statistical methods – that is, items 10, 12-17 of STROBE only. You may not have to address every item; just describe the major strengths and weaknesses of the authors’ descriptions of their statistical methods and results.
- For each important STROBE item:
o state whether you believe the STROBE item is met or not,
o support your judgment with proof or examples from the paper, and
o describe why this inclusion or exclusion is important / how it will impact on the reader’s understanding and decision making.
- The 400-500 words is a guideline not a rule. There are no penalties for exceeding this guideline.
- There are no marks for adding a reference list. Referencing is optional.
Question 2 (22 marks) Note: Students will get different answers as the data sets differ.
Using the data set assigned to you for your Assignments address the following research question:
Does myopia status predict sedentary hours per week after correcting for age in the population of young adult Australians?
Notes:
- You should only use the variables ‘sed’, ‘myopia’ and ‘age’.
- Correcting for ‘age’ is just including ‘age’ in the regression model. When age is in the model all other variables are corrected for it.
- Do report the results of your descriptive analyses
o Well labelled graphs can be copied from R Commander
o Summary statistics and tables should be manually typed
o Summarise the main findings of your descriptive analyses in words and describe how these findings inform your expectations and interpretation of the more complex models.
- Do report the results of your statistical inference and/or regression models
o Any fitted regression models should be manually typed and described in the text.
o Any hypothesis tests should contain all relevant information (use the 5 step method to be sure)
o Any other results such as confidence intervals should be manually typed and described in the text.
o Summarise the main findings of your regression model and statistical inference in one or two paragraphs.
- Do remember to answer the research question
o Write a final paragraph which summarises the key findings of your analysis and your answer to the research question.
- Do check the Learning Guide for the marking criteria
- Do write your answers yourself and keep them private.