Duplex: Duplex Ultrasonography for Detecting Peripheral Aterial...

In R4HCR: R for Health Care Research

Duplex Ultrasonography for Detecting Peripheral Aterial Disease.

Description

Diagnostic performance of duplex and color-guided duplex for detecting peripheral arterial disease (PAD) in 14 studies. PAD is defined as stenosis of 50-99% or an occlusion.

Usage

Duplex

Format

A data frame with 14 observations on the following 6 variables.

study

Name of study

test

Type of ultrasound (Color or Duplex)

tp

The number of true positive test results.

fn

The number of false negative test results.

tn

The number of true negative test results.

fp

The number of false positive test results.

Source

de Vries SO, Hunink MG, Polak JF. Summary receiver operating characteristic curves as a technique for meta-analysis of the diagnostic performance of duplex ultrasonography in peripheral arterial disease. Acad Radiol. 1996 Apr;3(4):361-9. doi: 10.1016/s1076-6332(96)80257-1. PMID: 8796687.

Examples

require(metafor); require(meta)

data(Duplex, package = "R4HCR")

# Fitting the common effects model.

Duplex <- escalc(
  measure = "OR",
  add = 0.5,
  to = "all",
  ai = tp,
  bi = fp,
  ci = fn,
  di = tn,
  data = Duplex)

Duplex <- within(Duplex,
{
  S = log((fp + 0.5)/(tn + 0.5)) + log((tp + 0.5)/(fn + 0.5))
}
)

ma <- metagen(TE = yi, seTE = vi, data = Duplex,sm = "OR")

metareg(ma, formula = S,method = "FE")

R4HCR documentation built on Sept. 30, 2024, 9:46 a.m.