DTAXG2 {DTAXG}

Two Diagnostic Tests Assessment in the Absence of Gold Standard

Description

To calculate the sensitivity and specificity for two diagnostic tests in the absence of gold standard using the Bayesian method. The prior information of sensitivity and specificity must be provided.

Usage

DTAXG2(group1,group2,
    prior.se.group1,prior.sp.group1,
    prior.se.group2,prior.sp.group2,
    prior.pi,n.sample,n.burnin,SUM)

Arguments

group1

vector of 0 and 1, and 1 indicates the positive

group2

vector of 0 and 1, and 1 indicates the positive

prior.se.group1

the prior range of sensitity of group1

prior.sp.group1

the prior range of specificity of group1

prior.se.group2

the prior range of sensitity of group2

prior.sp.group2

the prior range of specificity of group2

prior.pi

the prior range of detection rate

n.sample

the number of the Gibbs sampling, defalt is 12000

n.burnin

the number of the burn-in in Gibbs sampling, defalt is 2000

SUM

wheter to return the summary results, defalt is 'TRUE'

Value

table

if 'SUM' is TRUE, the Q50, Q2.5, and Q97.5 of sensitivity and specificity will be shown

PI

detection rate

S1

sensitivity of group1

S2

sensitivity of group2

C1

specificity of group1

C2

specificity of group2

Note

Please feel free to contact us, if you have any advice and find any bug!

Update description:

more functions will be included in 'DATXG' package!

Author(s)

Zhicheng Du<[e-mail]>, Yuantao Hao<[e-mail]>

References

Haiyan Gu, Qiguang Chen. Diagnostic Test Assessment in the Absence of Gold Standard. Zhong Guo Wei Sheng Tong Ji (in Chinese). 1999. 16(4): 203-205.

Examples

group1=c(rep(1,86),rep(0,64))
group2=c(rep(1,27),rep(0,86-27),rep(1,5),rep(0,64-5))
prior.se.group1=c(0.5,0.85)
prior.sp.group1=c(0.8,1)
prior.se.group2=c(0.1,0.5)
prior.sp.group2=c(0.1,0.5)
prior.pi=c(0.66,0.67)

rst=DTAXG2(
  group1,
  group2,
  prior.se.group1,
  prior.sp.group1,
  prior.se.group2,
  prior.sp.group2,
  prior.pi,
  n.sample=120,
  n.burnin=20)

print(rst)