My own toolbox in my small workshop is a mix of some old, worn, well proven tools and some newcomers. This package should be seen as something like that.
I have tried to collect tools and functions from other packages that I use regularly in addition to functions that I have written myself to fill use cases, that I have not been able to find solutions to elsewhere.
In documenting and testing the package, I have used [OpenAI's](https://beta.openai.com/overview) chatgpt with [gpttools](https://jameshwade.github.io/gpttools/). The chatgpt is an interesting tool, that is in no way perfect, but it helps with tedious tasks. Both `gpttools` and [`gptstudio`](https://michelnivard.github.io/gptstudio/) are interesting implementations in R and RStudio.
Note that, if handled, CPR numbers (social security numbers) should be handled with care as they a considered highly sensitive data.
The CPR number is structured as _DDMMYY-XXXX_, with the 1st _X_ designating decade of birth, the last _X_ designate binary gender (not biological sex) dependent on even/uneven as female/male, and the last for digits are used in a modulus calculation to verify the validity of the CPR number. Foreigners and unidentified persons are given temporary CPR numbers including letters.
More information can be found on [cpr.dk](https://cpr.dk).
Note, that all CPR numbers used in examples are publicly known or non-organic.
### age_calc()
The age_calc() function was created as a learning exercise and functions similarly to `lubridate::time_length()`.
Checks validity of CPR numbers according to the [modulus 11 rule](https://cpr.dk/cpr-systemet/opbygning-af-cpr-nummeret). Note that due to limitations in the possible available CPR numbers, this rule [does not apply to all CPR numbers after 2007](https://cpr.dk/cpr-systemet/personnumre-uden-kontrolciffer-modulus-11-kontrol).
Including CPR numbers with letters gives a warning and `NA`, as it can not be checked by the modulus 11 function. Should be used with care, see the message.
### cpr_dob()
Extracts date of birth (DOB) from a CPR number. Accounts for the decade of birth. [See earlier](#cpr-intro).
Plots odds ratios with 95 % confidence intervals. Performs binary logistic regression for outcome factors with two (2) levels and ordinal logistic regression for outcome factors with more than two levels. Mind relevant assumptions.
ci_plot(ds = talos, x = "rtreat", y = "mrs_1", vars = c("hypertension","diabetes"))
```
### generic_stroke()
For learning purposes. Uses annonymized data from the [TALOS trial](https://doi.org/10.1161/STROKEAHA.117.020067) to output a Table 1 (with `gtsummary::tbl_summary()`), plotting the so-called grotta-bars based on mRS scores (with `rankinPlot::grottaBar()`) and a ordinal logistic regression model plot (with `stRoke::ci_plot()`).