hba1c {MethComp} | R Documentation |
Measurements of HbA1c from Steno Diabetes Center
Description
Three analysers (machines) for determination of HbA1c (glycosylated haemoglobin) were tested on samples from 38 individuals. Each had drawn a venous and capillary blood sample. These were analysed on five different days.
Format
A data frame with 835 observations on the following 6 variables.
dev
Type of machine used. A factor with levels
BR.V2
,BR.VC
andTosoh
.type
Type of blood analysed (capillary or venous). A factor with levels
Cap
Ven
item
Person-id. A numeric vector
d.samp
Day of sampling.
d.ana
Day of laboratory analysis.
y
The measured value of HbA1c.
Details
In the terminology of method comparison studies, methods is the
cross-classification of dev
and type
, and replicate is
d.ana
. It may be of interest to look at the effect of time between
d.ana
and d.samp
, i.e. the time between sampling and analysis.
Source
Bendix Carstensen, Steno Diabetes Center.
References
These data were analysed as example in: Carstensen: Comparing and predicting between several methods of measurement, Biostatistics 5, pp. 399–413, 2004.
Examples
data(hba1c)
str(hba1c)
hb1 <- with( hba1c,
Meth( meth = interaction(dev,type),
item = item,
repl = d.ana-d.samp,
y = y, print=TRUE ) )