Homelessness indicator development

[shijiaSMH]

Will add a homelessness function when specific implementation is agreed by group, based on conceptual and empirical evidence

[shijiaSMH]

Function development - skeleton codes

Homelessness <- function(data, ipdiagnosis, erdiagnosis){
data[, homeless := F]
 data[genc_id %in% ipdiagnosis[diagnosis_code %in% c('Z590', 'Z591')]$genc_id |
     genc_id %in% erdiagnosis[er_diagnosis_code %in% c('Z590', 'Z591')]$genc_id, homeless := T]
}

Documentation

• Purpose: This function returns an encounter-based homelessness flag using ICD-10-CA diagnosis codes.
• Input arguments: data = a genc_id list, ipdiagnosis, erdiagnosis
• The accuracy of this function relies on maintained of Z59.0 Homelessness and Z59.1 Inadequate Housing codes in hospitals
• Pre-2018 limitations: It's expected to see significantly lower rate of homelessness before 2018 than rates after 2018 due to CIHI mandate.
• Use recommendation: We recommend to use this flag in descriptive analysis
• Report recommendation: This flag is a validated, adapted flag of ICES validated homelessness indicator
• Reference 1: CIHI mandate to code Z59.0 Homelessness in 2018: https://www.cihi.ca/en/better-quality-hospital-data-for-identifying-patients-experiencing-homelessness
• Reference 2: ICES validated homelessness indicator 2018: https://bmjopen.bmj.com/content/9/10/e030221
• Reference 3: ICES validated homelessness indicator pre-proof 2024: pre-proof.pdf

[loffleraSMH]

Please use the exact same argument/code structure as in covid_flag() function (see here: https://github.com/GEMINI-Medicine/Rgemini/blob/master/R/covid_flag.R).