Table 3.

Equations to estimate median and 25th and 75th percentiles of ACR from a PCR measurement, on the basis of quantile regression models for log(ACR) containing only the linear spline terms for log(PCR)

Range of PCR, mg/gEquation to Estimate Median Log(ACR)Equation to Estimate 25th Percentile Log(ACR)Equation to Estimate 75th Percentile Log(ACR)
PCR<400.9518+0.1264×log(PCR)0.5528+0.1297×log(PCR)1.4520+0.1074×log(PCR)
PCR 40 to <60−1.2568+0.7251×log(PCR)−0.1416+0.3179×log(PCR)−3.7193+1.5092×log(PCR)
PCR 60 to <250−6.7837+2.0751×log(PCR)−6.2467+1.8092×log(PCR)−4.9571+1.8116×log(PCR)
PCR 250 to <1000−2.9649+1.3834×log(PCR)−7.1833+1.9788×log(PCR)−1.4477+1.1760×log(PCR)
PCR≥1000−0.0239+0.9577×log(PCR)−0.0867+0.9264×log(PCR)−0.1902+0.9939×log(PCR)
• Log refers to the natural logarithm, so ACR=exp[log(ACR)]=2.71828log(ACR). Median predicted ACR=exp[median of predicted log(ACR)]. ACR and PCR are in milligrams per gram.