RISCA (version 1.0.7)

dataDIVAT5: The Aggregated Kidney Graft Survival Stratified By The 1-year Serum Creatinine.

Description

A data frame that presents the aggregated outcomes per center of 5943 French kidney transplant recipients from the DIVAT cohort. It was used by Combescure et al. (2016).

Usage

data(dataDIVAT5)

Format

A data frame with 106 observations for the 8 following variables:

classe

This numeric vector represents the groups of recipients defined using the 1-year serum creatinine. 1 is the first group with the lowest values of 1-year serum creatinine.

n

This numeric vector represents the number of recipients at the baseline (date of the transplantation) in each group.

year

This numeric vector represents the post transplant time (in years).

surv

This numeric vector represents the survival probabilities at each year (obtained using the Kaplan and Meier estimator from the individual data).

n.risk

This numeric vector represents the number of subjects at-risk of the event at the corresponding year.

proba

This numeric vector represents the proportion of the patients in a center which belong to the corresponding group.

marker.min

This numeric vector represents the minimum value of the interval of the 1-year serum creatinine (in \(\mu mol/l\)).

marker.max

This numeric vector represents the maximum value of the interval of the 1-year serum creatinine (in \(\mu mol/l\)).

centre.num

This numeric vector represents the centers.

Details

The immunology and nephrology department of the Nantes University hospital constituted a data bank with the monitoring of medical records for kidney and/or pancreas transplant recipients. Here, we considered a subpopulation of 4195 adult patients and who had received a first kidney graft between January 1996 and Jun 2008. Five centers participated. A total of 511 graft failures were observed (346 returns to dialysis and 165 deaths with a functional kidney). Based on this database, we constructed an aggregated dataset to perform a meta-analysis on 5 published monocentric studies. The medical objective was to evaluate whether 1-year serum creatinine (Cr) is a good predictive marker of graft failure. Cr is a breakdown product and is removed from the body by the kidneys. If kidney function is abnormal, blood Cr levels increase.

References

Combescure et al. A literature-based approach to evaluate the predictive capacity of a marker using time-dependent Summary Receiver Operating Characteristics. Stat Methods Med Res, 25(2):674-85, 2016. <doi: 10.1177/ 0962280212464542>

Examples

data(dataDIVAT5)

# Kaplan Meier estimations of the graft survival in the first center
plot(dataDIVAT5$year[dataDIVAT5$centre.num==1],
 dataDIVAT5$surv[dataDIVAT5$centre.num==1],
 xlab="Post transplantation time (years)", ylab="Graft survival",
 ylim=c(0.7,1), xlim=c(0, 9), type="n")

# Goup 1
lines(c(0, dataDIVAT5$year[dataDIVAT5$centre.num==1 &
 dataDIVAT5$classe==1]),
 c(1, dataDIVAT5$surv[dataDIVAT5$centre.num==1 &
 dataDIVAT5$classe==1]),
 type="b", col=1, lty=1, lwd=2)

# Goup 2
lines(c(0, dataDIVAT5$year[dataDIVAT5$centre.num==1 &
 dataDIVAT5$classe==2]),
 c(1, dataDIVAT5$surv[dataDIVAT5$centre.num==1 &
 dataDIVAT5$classe==2]),
 type="b", col=2, lty=2, lwd=2)

# legend
legend("bottomleft", c("group #1 (1-year Cr<4.57)",
 "group #2 (1-year Cr>4.57)"), col=c(1, 2),
 lty=c(1, 2), lwd=c(2, 2))