PUBH7611 Epidemiology in Practice
Assessment 3: Analysis & Interpretation of Epidemiologic Data

Weighting: 40%

Context:

This assessment is based on the learning objectives and concepts in Weeks 4-12 (including readings, lecture material and relevant workshop exercises) as well as previous knowledge from PUBH7600 Introduction to Epidemiology.

There are a total of 100 marks and this assessment will contribute 40% towards the total assessment for this subject.

Your assessment should be submitted in the form of a publishable journal article (based on the instructions for the write-up, specified in the instructions for Assessment 3). Assessments should be submitted as a Word document via Turnitin on Blackboard. Be as concise as possible in your answers (without compromising on required detail) and note that there are specified spacelimitations for each component.

Late assessments will not be accepted without prior approval. If an extension is required, you must apply online via my.UQ (see the SPH policy on late submissions and extensions).

Please note that this is an individual exercise and should be done independently of others. The University of Queensland takes academic misconduct (including collusion and plagiarism) very seriously. Please refer to UQ’s student policy regarding student integrity and misconduct (https://ppl.app.uq.edu.au/content/3.60.04-student-integrity-and-misconduct) for further information. Before submitting this assessment, you need to ensure that you have completed the online Academic Integrity Tutorial, which can be accessed via SI-net. By submitting your assessment via Turnitin you declare that you are aware of the consequences of plagiarism and the principles associated with preventing plagiarism. The University of Queensland has approved the use of plagiarism detection software and the School uses this as part of their check for academic misconduct.2

TASK DESCRIPTION:

1) Is alcohol consumption (exposure) causally associated with depression (outcome)?

2) Is there an interaction between alcohol consumption and sex on the risk of depression?

3) Is there an interaction between alcohol consumption and general health status on the risk of depression?

4) Graphically display the interactions above.

Table 1 contains a list of the variables in the Stata dataset that will be used for your analyses.

Table 1: Description of variables contained in Assignment3 dataset

ADDITIONAL INSTRUCTIONS:

Variable categorisations:

1. The outcome (depression) should be categorised as a binary variable. Categorise scores of ≤9 as the reference category of minimal to mild depression. Scores of ≥10 equate to the presence of moderate to severe depression.
2. Alcohol consumption (the exposure) should be categorised as a binary variable. Please categorise 4 drinks or less on a single occasion as the reference category (low risk drinking) and 5 or more alcoholic drinks on a single occasion as your exposed category (risky drinking). Be careful of missing values.
3. General health status (health) should be categorised as a binary variable. Categorise ‘very good’, ‘excellent’ and ‘good’ as the reference category and ‘fair’ to ‘poor’ and as your exposed category.
4. Body mass index (BMI) should be categorised as a binary variable. Someone is classified as being obese if their body mass index (BMI) is ≥30kg/m2 . Anyone with a BMI <30 kg/m2 should be included in the reference category. BMI is calculated by dividing someone’s weight (in kilograms) by someone’s height squared (in metres) i.e., BMI = weight(kg)/(height(m)2 ). Be careful of missing values.
5. Smoking status should be classified as a categorical variable with 3 categories – never smoker (reference category), ex/past smoker, and current smoker. To create this new variable, you will need to use information from both of the smoking variables (smoking_any and smoking_current) in your dataset.
6. The variables age (continuous), sex (male=reference category), and education (no=reference category) and marital (married=reference category) and can be left as they are already defined in the dataset for all analyses. Some characteristics will only be used to describe the participants.

Analyses:

Write-up:

Results:

Discussion:

Supplementary Material (Appendix):

Other considerations for marking:

Marks will be awarded based on the structure of your assessment and writing. Headings and subheadings should be used. The flow of ideas should be logical (rather than jumping from one idea to another and back again, for example). Minimal grammatical, spelling or punctuation errors and appropriate use of English language and scientific writing style.

Provide a reference list of all articles/sources cited in your assessment; use Harvard or Vancouver style.

Kroenke K, Spitzer RL, William JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med 2001; 16: 1606-13. 

PHQ-9 has a range of 0 to 27 calculated from responses to the following questions:

Over the last 2 weeks, how often have you been bothered by any of the following problems?

PUBH7611 Assessment 3 – Analysis & Interpretation Summary Marking Matrix