age_from_chi {phsmethods}

Extract age from the CHI number

Description

age_from_chi takes a CHI number or a vector of CHI numbers and returns the age as implied by the CHI number(s). If the Date of Birth (DoB) is ambiguous it will return NA. It uses dob_from_chi().

Usage

age_from_chi(
  chi_number,
  ref_date = NULL,
  min_age = 0,
  max_age = NULL,
  chi_check = TRUE
)

Arguments

chi_number

a CHI number or a vector of CHI numbers with character class.

ref_date

calculate the age at this date, default is to use Sys.Date() i.e. today.

min_age, max_age

optional min and/or max dates that the DoB could take as the century needs to be guessed. Must be either length 1 for a 'fixed' age or the same length as chi_number for an age per CHI number. min_age can be age based on common sense in the dataset, whilst max_age can be age when an event happens such as the age at discharge.

chi_check

logical, optionally skip checking the CHI for validity which will be faster but should only be used if you have previously checked the CHI(s), the default (TRUE) will to check the CHI numbers.

Value

an integer vector of ages in years truncated to the nearest year. It will be the same length as chi_number.

Examples

age_from_chi("0101336489")

library(tibble)
library(dplyr)
data <- tibble(chi = c(
  "0101336489",
  "0101405073",
  "0101625707"
), dis_date = as.Date(c(
  "1950-01-01",
  "2000-01-01",
  "2020-01-01"
)))

data %>%
  mutate(chi_age = age_from_chi(chi))

data %>%
  mutate(chi_age = age_from_chi(chi, min_age = 18, max_age = 65))

data %>%
  mutate(chi_age = age_from_chi(chi,
    ref_date = dis_date
  ))