Date to numeric conversion in datashield

Support Analyst Support
1

Let’s imagine a clinic keeping track of their patients’ DoB and first visits.

Birth Visit
1959-11-22 2021-06-12
1961-01-07 2021-06-25
1992-06-19 2018-12-26

In DataSHIELD, we would like to pool ages of diagnoses, based on dates of birth and visit, like so:

Birth Visit Age of Diagnosis
1959-11-22 2021-06-12 61
1961-01-07 2021-06-25 60
1992-06-19 2018-12-26 26

I am fairly certain this should be possible through assignment operations but I was not able to find how to do this. Do I have no choice but to compute AoD locally, before creating the table on DataSHIELD?

Thanks in advance!

2

Hi Ahmet,

The dsSwissKnifeClient package has some functions to deal will dates (see for example dssAddDaysInterval). However, i have never use this package so i can’t give any further information.

Demetris

1 Like
3

Hi Ahmet,

ISGlobal has produced a package called dsDates (GitHub: isglobal-brge/dsDates), but I don’t know if it is still supported.

Stuart

1 Like
4

dssAddDaysInterval in conjunction with dssDeriveColumn did the trick!

library(dsSwissKnifeClient)

# Compute Age in Days
dsSwissKnifeClient::dssAddDaysInterval(
  newobj='D_',
  df='D',
  description.list= list(
    'age_in_days' = list( end_date='Visit',start_date ='Birth')
  ),
  datasources= conns)

# Compute Age in Years

dsSwissKnifeClient::dssDeriveColumn('D_', 'age_in_years', 'age_in_days/365', datasources = conns)