Estimate the Case Fatality Risk Ratio to complement stratified CFR calculations

cfr_riskratio.md

We can estimate the relative risk for the causal interpretation of CFR estimates (Lipsitch et al.)

two-by-two table

	non-death	death
44-younger	311	768
45+older	51	299

CFR (stratified)

• 44-younger: CFR = 768/(311+768) = 0.71
• 45+older: CFR = 299/(51+299) = 0.85

Case Fatality Risk Ratio:

library(epitools)
rr_matrix <- matrix(c(311, 51, 768, 299),nrow = 2, ncol = 2)
epitools::riskratio(rr_matrix)
#> $data
#>           Outcome
#> Predictor  Disease1 Disease2 Total
#>   Exposed1      311      768  1079
#>   Exposed2       51      299   350
#>   Total         362     1067  1429
#> 
#> $measure
#>           risk ratio with 95% C.I.
#> Predictor  estimate    lower    upper
#>   Exposed1 1.000000       NA       NA
#>   Exposed2 1.200227 1.133086 1.271346
#> 
#> $p.value
#>           two-sided
#> Predictor    midp.exact fisher.exact   chi.square
#>   Exposed1           NA           NA           NA
#>   Exposed2 3.179312e-08 4.200177e-08 9.982161e-08
#> 
#> $correction
#> [1] FALSE
#> 
#> attr(,"method")
#> [1] "Unconditional MLE & normal approximation (Wald) CI"

following https://sphweb.bumc.bu.edu/otlt/MPH-Modules/PH717-QuantCore/PH717-Module8-CategoricalData/PH717-Module8-CategoricalData6.html

^{Created on 2024-08-13 with reprex v2.1.0}