L1: Questions and time in epidemiologic studies
Readings
Slides
Below are links to the two sets of slides used this week: an introduction to the course and Lecture 1. You can download each slide deck individually by clicking on the image of the title slide for each course session, or all slides by clinking the download link below.
Notes
Notation
Everyone in this course has the preparation required to master the material presented. There is no advanced math in this class, but you may see notation you have not seen before. Get in the habit of translating all notation you come across in this course into English language sentences and ask questions about notation that is unfamiliar.
Some examples:
\(\sum_{i=1}^nX_i\): Sum \(X_i\) over all units (up to unit \(n\)) indexed by \(i\)
\(\prod_{k=1}^m d_k\): multiply \(d\) over all units (up to unit \(m\)) indexed by \(k\)
Line diagrams
Drawing line diagrams is a great skill to develop an understanding of the importance of time scales, censoring, and late entry. For extra practice, return to slide 34 of Thursday’s slide deck and draw a line diagram with time since entry into HIV care on the \(x\)-axis and study id on the \(y\)-axis. What happens to people who enter care in January 2018 and survive until the study closes on December 31, 2020?
For R code to produce line diagrams, please see the Resources section of the site.
Videos
Recordings of lectures are available on the EPID 722 Sakai site.
Optional readings
Further reading about time in epidemiologic research
Optional reading (for fun) about learning science and math
Exercise
There is no exercise this week. If you struggled with the line diagrams during Thursday’s lecture, take some time to practice by repeating the examples we worked through in class. Interested in making your own line diagrams in R? See the code in the Resources section.
Questions
Please use the form below to submit your questions about this week’s reading.
NOTE: Most weeks, questions will be due by Monday at 9am. However, this week, you have until Thursday at 3pm to submit your question. We will address any themes running though the questions next week.