upcr_uacr: Convert UPCR to UACR with clinical covariates

In kfre: Kidney Failure Risk Equation (KFRE) Tools

Convert UPCR to UACR with clinical covariates

Description

Implements the equation reported by Sumida et al. for converting urine protein–creatinine ratio to urine albumin–creatinine ratio, with adjustments for sex, diabetes, and hypertension.

Usage

upcr_uacr(
  df,
  sex_col,
  diabetes_col,
  hypertension_col,
  upcr_col,
  female_str = "female"
)

Arguments

df	A data.frame containing the required columns.
sex_col	Column name with sex labels, character. Example: "sex".
diabetes_col	Column name with diabetes indicator, 0 or 1, or logical. Example: "diabetes".
hypertension_col	Column name with hypertension indicator, 0 or 1, or logical. Example: "hypertension".
upcr_col	Column name with UPCR values. Units should match those used to derive the model in Sumida et al. (mg/g). If your data use different units, convert before calling.
female_str	String that denotes female in sex_col. Default is "female".

Details

The function applies a piecewise log transformation of UPCR with cut points at 50 and 500, and adds covariate adjustments for sex, diabetes, and hypertension, then exponentiates to return UACR. Valid rows require non missing diabetes and hypertension indicators. Sex is mapped to an indicator using female_str.

Value

A numeric vector of UACR values, length nrow(df). Non valid rows return NA_real_.

References

Sumida, K., Nadkarni, G. N., Grams, M. E., Sang, Y., Ballew, S. H., Coresh, J., Matsushita, K., Surapaneni, A., Brunskill, N., Chadban, S. J., Chang, A. R., Cirillo, M., Daratha, K. B., Gansevoort, R. T., Garg, A. X., Iacoviello, L., Kayama, T., Konta, T., Kovesdy, C. P., Lash, J., Lee, B. J., Major, R. W., Metzger, M., Miura, K., Naimark, D. M. J., Nelson, R. G., Sawhney, S., Stempniewicz, N., Tang, M., Townsend, R. R., Traynor, J. P., Valdivielso, J. M., Wetzels, J., Polkinghorne, K. R., and Heerspink, H. J. L. (2020). Conversion of urine protein-creatinine ratio or urine dipstick protein to urine albumin-creatinine ratio for use in chronic kidney disease screening and prognosis. Annals of Internal Medicine, 173(6), 426-435. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.7326/M20-0529")}

Examples

df <- data.frame(
  sex = c("female", "male"),
  diabetes = c(1, 0),
  hypertension = c(0, 1),
  upcr = c(100, 400)  # mg/g (or same ratio units)
)
upcr_uacr(df, "sex", "diabetes", "hypertension", "upcr")

kfre documentation built on Aug. 28, 2025, 9:09 a.m.