pooledROC.emp {AROC} | R Documentation |

## Empirical estimation of the pooled ROC curve.

### Description

Estimates the pooled ROC curve using the empirical estimator proposed by Hsieh and Turnbull (1996).

### Usage

```
pooledROC.emp(y0, y1, p = seq(0, 1, l = 101), B = 500,
method = c("ncoutcome", "coutcome"))
```

### Arguments

`y0` |
Diagnostic test outcomes in the healthy group. |

`y1` |
Diagnostic test outcomes in the diseased group. |

`p` |
Set of false positive fractions (FPF) at which to estimate the covariate-adjusted ROC curve. |

`B` |
An integer value specifying the number of bootstrap resamples for the construction of the confidence intervals. By default 500. |

`method` |
A character string specifying if bootstrap resampling (for the confidence intervals) should be done with or without regard to the disease status (“coutcome” or “noutcome”). In both cases, a naive bootstrap is used. By default, the resampling is done conditionally on the disease status. |

### Value

As a result, the function provides a list with the following components:

`call` |
the matched call. |

`p` |
Set of false positive fractions (FPF) at which the pooled ROC curve has been estimated |

`ROC` |
Estimated pooled ROC curve, and corresponding 95% confidence intervals (if required) |

`AUC` |
Estimated pooled AUC, and corresponding 95% confidence intervals (if required). |

### References

Hsieh, F., and Turnbull, B.W. (1996). Nonparametric and semiparametric estimation of the receiver operating characteristic curve, The Annals of Statistics, 24, 25-40.

### See Also

`AROC.bnp`

, `AROC.bsp`

, `AROC.sp`

, `AROC.kernel`

, `pooledROC.BB`

or `pooledROC.emp`

.

### Examples

```
library(AROC)
data(psa)
# Select the last measurement
newpsa <- psa[!duplicated(psa$id, fromLast = TRUE),]
# Log-transform the biomarker
newpsa$l_marker1 <- log(newpsa$marker1)
m0_emp <- pooledROC.emp(newpsa$l_marker1[newpsa$status == 0],
newpsa$l_marker1[newpsa$status == 1], p = seq(0,1,l=101), B = 500)
summary(m0_emp)
plot(m0_emp)
```

*AROC*version 1.0-4 Index]