fat: Measurements of subcutaneous and visceral fat

In MethComp: Analysis of Method Comparison studies

Description

43 persons had Subcutaneous and Visceral fat thickness measured at Steno Diabetes Center in 2006 by two observers; all measurements were done three times. The interest is to compare the measurements by the two observers. Persons are items, observers are methods, the three replicates are exchangeable within (person,observer)=(item,method)

Usage

data(fat)

Format

A data frame with 258 observations on the following 6 variables.

Id

Person id.

Obs

Observers, a factor with levels KL and SL.

Rep

Replicate — exchangeable within person and observer.

Sub

Subcutaneous fat measured in cm.

Vic

Visceral fat measured in cm.

Examples

data(fat)
str(fat)
vic <- Meth( fat, meth=2, item=1, repl="Rep", y="Vic" )
str(vic)
BA.est( vic, linked=FALSE )

Example output

'data.frame':	258 obs. of  5 variables:
 $ Id : num  1 1 1 3 3 3 5 5 5 11 ...
 $ Obs: Factor w/ 2 levels "KL","SL": 1 1 1 1 1 1 1 1 1 1 ...
 $ Rep: num  1 2 3 1 2 3 1 2 3 1 ...
 $ Sub: num  1.6 1.7 1.7 2.8 2.9 2.8 2.7 2.8 2.9 3.9 ...
 $ Vic: num  4.5 4.4 4.7 6.4 6.2 6.5 3.6 3.9 4 4.3 ...
The following variables from the dataframe
"fat" are used as the Meth variables:
meth: Obs 
item: Id 
repl: Rep 
   y: Vic 
       #Replicates
Method          3 #Items #Obs: 258 Values:  min med max
    KL         43     43       129          2.0 3.9 6.5
    SL         43     43       129          2.3 4.1 6.7
Classes ‘Meth’ and 'data.frame':	258 obs. of  5 variables:
 $ meth: Factor w/ 2 levels "KL","SL": 1 1 1 1 1 1 1 1 1 1 ...
 $ item: Factor w/ 43 levels "1","2","3","4",..: 1 1 1 3 3 3 5 5 5 11 ...
 $ repl: Factor w/ 3 levels "1","2","3": 1 2 3 1 2 3 1 2 3 1 ...
 $ y   : num  4.5 4.4 4.7 6.4 6.2 6.5 3.6 3.9 4 4.3 ...
 $ Sub : num  1.6 1.7 1.7 2.8 2.9 2.8 2.7 2.8 2.9 3.9 ...

 Conversion between methods:
            alpha   beta sd.pred LoA-lo LoA-up
To: From:                                     
KL  KL      0.000  1.000   0.273 -0.545  0.545
    SL     -0.155  1.000   0.364 -0.883  0.573
SL  KL      0.155  1.000   0.364 -0.573  0.883
    SL      0.000  1.000   0.245 -0.490  0.490

 Variance components (sd):
   IxR   MxI   res
KL   0 0.181 0.193
SL   0 0.181 0.173

MethComp documentation built on May 2, 2019, 5:06 p.m.