Assignment for candidates for the position - Statistician - Infection Epidemiology and Modelling (1884-SM) at the Norwegian Institute of Public Health

Email to applicants

We will be sending you a basic skills test that will test your skills in R and the surveillance of infectious diseases. As a part of this test, you will need to sign up for a free GitHub account (https://github.com/join).

Background

This is an assignment related to infectious disease surveillance that will test your skills in R. The deadline for submission of the test is found in your email. Please read through all of this document before beginning the test.

The scenario is broadly as follows:

You are responsible for Disease X. There is a data file data_raw/individual_level_data.RDS which contains individual level daily data for Disease X for 422 municipalities between 2000-01-01 and 2010-12-31. Each row of this dataset corresponds to 1 sick person on that date. To be more explicit:

• If there are 100 rows for Municip0301 on 2000-01-01 it means that there were 100 sick people in Municip0301 on 2000-01-01.
• If there are 0 rows for Municip0301 on 2000-01-01 it means that there were 0 sick people in Municip0301 on 2000-01-01.

For each municipality you will use the data between 2000-01-01 and 2009-12-31 to build a regression model that predicts the expected number of sick people. You will then use this model to predict the expected number of sick people between 2010-01-01 and 2010-12-31. You will then produce Excel sheets and graphs that contain information regarding the suspected outbreaks in 2010.

The data file data_raw/norwayLocations.RDS contains a data.frame that links location (e.g. municip0301) to municipName (e.g. Oslo) and county (e.g. county03) and countyName (e.g. Oslo). These are real municipality numbers (kommunenummer) based on the 2019 municipality lists (https://en.wikipedia.org/wiki/List_of_municipality_numbers_of_Norway).

English <-> Norwegian

municipality = kommune

county = fylke

Assumptions

• You can assume that the population for each municipality is 10000 people and this number remains constant throughout the entire period.
• Even though the data represents real municipalities from Norway, DO NOT download real population data for Norway and use it.

Test: Setup

1. Create a new repository called xx_01_submission in GitHub (https://help.github.com/articles/creating-a-new-repository/)
2. Clone your new repository to your local computer (https://help.github.com/articles/cloning-a-repository/)
3. Download the following zip file: https://github.com/folkehelseinstituttet/xx_01/archive/master.zip
4. Copy the files into your local xx_01_submission folder

Folder/File Setup

You are required to put your code in the following locations:

• All functions are to be placed in .R files located in the code folder (e.g. see code/CreateFakeData.R)
• You will write your master file/script/code (that runs all of the requested analyses by calling the functions in code/*) in Run.R (this file already has a few lines of code in it)
• Your results will be saved in the results folder

Test: Coding

5. Load in the data file data_raw/individual_level_data.RDS
6. Create a dataset that contains the aggregated number of sick people per day per municipality.
7. Ensure that your aggregated dataset includes rows/days with zero sick people (e.g. if there were no rows for 2000-01-01/Municip0301 in data_raw/individual_level_data.RDS then your aggregated dataset will still need to have one row for 2000-01-01/Municip0301 with the value 0).
8. Collapse your data down to iso-year/iso-weeks for each municipality. If you are not familiar with iso-week/years, there is information available at https://en.wikipedia.org/wiki/ISO_week_date and https://rdrr.io/cran/surveillance/man/isoWeekYear.html

Do the following for each of the 422 municipalities:

9. Split the data into training data (2000-01 to 2009-53) and production data (2010-01 to 2010-52)
10. Use the training data to create a regression model that predicts the expected weekly number of sick people. You will need to determine an appropriate regression model (e.g. does the data have seasonality? a trend?). You can do this by either a) examining the code in the function CreateFakeDataForOneMunicipality inside code/CreateFakeData.R or b) by performing your own statistical analyses. Please write a comment above your model indicating if you examined the code or performed your own statistical analysis. We consider both techniques to be valid and neither choice will be penalized or rewarded over the other. Remember that you do not need to worry about the population changing over time.
11. For the training data, create a 2 standard deviation prediction interval
12. Identify the potential outbreaks in the training data (i.e. number of sick people > prediction interval)
13. Exclude the potential outbreaks from the training data
14. Refit the model using the new training data (without any outbreaks in it)
15. Create a 2 standard deviation prediction interval for the production data
16. Identify the potential outbreaks in the production data
17. Create and save an excel sheet with the potential outbreaks in results/municipality_results/outbreaks_MunicipXXXX.xlsx (i.e. one Excel file for each municipality)
18. Create and save a figure that provides a good overview of the situation in the municipality in results/municipality_results/overview_MunicipXXXX.png (i.e. one figure for each municipality). An example of one such graph is available at https://github.com/folkehelseinstituttet/xx_01/blob/master/example_report/5218---overvaking-av-totaldodelighet-5218-uke-52.pdf

Note: the graphs must include titles with the real municipality name (e.g. Oslo instead of municip0301). This information is available in the data file data_raw/norwayLocations.RDS.

Test: Creative Assignment

Every week there is a meeting at Folkehelseinstituttet to discuss the current outbreak situation in Norway. The current date is 2010-12-31. You need to produce graph(s) and/or table(s) for this meeting that will give the meeting participants a good summary of the current situation for Disease X in Norway and the situation in the last few weeks. In this meeting you would have a maximum of 2 minutes to present, so your graph(s) and/or table(s) must be easily understood.

You may use external structural data files for this creative assigment (e.g. shapefiles for Norway) if you think it is appropriate.

Please save your graph(s) and/or table(s) into results/creative_assignment.

Please provide comments in your code that indicate which parts of your code produce the graph(s) and/or table(s) for this creative assignment.

Test: Submission

19. Commit your results and push them back to GitHub
20. Verify that your code is viewable in your GitHub repository on the internet (both in Run.R and in code/*.R)
21. Verify that in your GitHub repository on the internet you have 422 Excel files and 422 graphs in results/municipality_results/
22. Verify that in your GitHub repository on the internet you have graph(s) and/or table(s) in results/creative_assignment/
23. Send GryMarysol.Groneng@fhi.no and RichardAubrey.White@fhi.no an email with the link to your repository