401077 Introduction to Biostatistics, Autumn 2020
Assignment 3
Due Sunday June 7, 2020
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.
Question 1
(18 marks)
Read the paper Mirzaei, M., Taylor, R., Morrell, S., & Leeder, S. R. (2007). Predictors of blood pressure in a cohort of school-aged children.European Journal of Cardiovascular Prevention & Rehabilitation,14(5), 624-629.
Critically appraise of the statistical material in this paper against items 10, 12-17 of the STROBE checklist. Present your review as a short report (perhaps 600 words).
Note:
-Only review the provided paper Mirzaeiet al, 2007. Do not read any other papers.
-Restrict your review to how well Mirzaeiet 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:
ostate whether you believe the STROBE item is met or not,
osupport your judgment with proof or examples from the paper, and
odescribe why this inclusion or exclusion is important / how it will impact on the reader’s understanding and decision making.
-The 600 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)
This question requires you to analyse the unique assignment data set which I have created for you. This is labelled ‘dataforxxxxxxxx.RData’ where xxxxxxxx represents your Student ID number. This is the same data set which you used for Assignment 1. Read ‘Description of your data set.docx’ for the descriptions of the variables. Please assume that this data represents a random sample of the Framingham population.
Address the following research question:
Are gender and age independent predictors of diastolic blood pressure in the Framingham population?
Note: Independent predictors mean they both have statistically significant relationships with diastolic blood pressure when included in the same regression model. (You should address this question using linear regression and include associated descriptive analyses.)
Note: 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 any 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.
Also note:
-The only variables in the data set which could be relevant to answering this research question are ‘diabp’, ‘diabp_log’, ‘diabp_inverse’, ‘age’ and ‘sex’.
-Documenting your analysis plan is recommended but not required. (If your analysis report is complete then your plan must have been complete also.)
-Do
report the results of your descriptive analyses
oWell labelled graphs can be copied from R Commander
oSummary statistics and tables should be manually typed
oSummarise 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
oAny fitted regression models should be manually typed and described in the text.
oAny hypothesis tests should contain all relevant information (use the 5 step method to be sure)
oAny confidence intervals should be manually typed and described in the text.
oSummarise the main findings of your regression model and statistical inference in one or two paragraphs.
-Doremember to answer the research questions
oWrite a final paragraph which summarises the key findings of your analysis and your answers to the research question.
-Docheck the Learning Guide for the marking criteria
-Dowrite your answers yourself and keep them private.