[R] svykappa using the survey package

Muhuri, Pradip (AHRQ/CFACT) Pradip.Muhuri at ahrq.hhs.gov
Tue Jun 21 01:49:55 CEST 2016


Hello,

My goal is to calculate the weighted kappa measure of agreement between two factors  using the R  survey package.  I am getting the following error message (the console is appended below; sorry no data provided).

> # calculate survey Kappa
> svykappa(~xbpchek53+xcholck53, design)
Error in names(probs) <- nms : 
  'names' attribute [15] must be the same length as the vector [8]

I have followed the following major steps:

1) Used the "haven" package to read the sas data set into R.
2) Used the dplyr mutate() to create 2 new variables and converted to factors [required for the svykappa()?].
3) Created an object (named design) using the survey design variables and the data file.
4) Used the svykappa() to compute the kappa measure of agreement. 

I will appreciate if someone could give me hints on how to resolve the issue.

Thanks,

Pradip Muhuri

###############  The detailed console is appended below  ####################

> setwd ("U:/A_PSAQ")
> library(haven)
> library(dplyr)
> library(survey)
> library(srvyr)
> library(Hmisc)
> my_hc2013_data <- read_sas("pc2013.sas7bdat")
> 
> # Function to convert var names in upper cases to var names in lower cases
> lower <- function (df) {
+   names(df) <- tolower(names(df))
+   df
+ }
> my_hc2013_data <- lower(my_hc2013_data)
> 
> # Check the contents - Hmisc package (as above) required
> # contents(my_hc2013_data)
> 
> # create two new variables
> my_hc2013_data <- mutate(my_hc2013_data, 
+                          xbpchek53 = ifelse(bpchek53 ==1, 1,
+                             ifelse(bpchek53 %in% 2:6, 2,NA)), 
+                          xcholck53 = ifelse(cholck53 ==1, 1,
+                            ifelse(cholck53 %in% 2:6, 2,NA)))
> 
> # convert the numeric variables to factors for the kappa measure
> my_hc2013_data$xbpchek53 <- as.factor(my_hc2013_data$xbpchek53)
> my_hc2013_data$xcholck53 <- as.factor(my_hc2013_data$xcholck53)
> 
> # check whether the variables are factors
> is.factor(my_hc2013_data$xbpchek53)
[1] TRUE
> is.factor(my_hc2013_data$xcholck53)
[1] TRUE
> 
> 
> # check the data from the cross table
> addmargins(with(my_hc2013_data, table(bpchek53,xbpchek53 )))
        xbpchek53
bpchek53     1     2   Sum
     -9      0     0     0
     -8      0     0     0
     -7      0     0     0
     -1      0     0     0
     1   19778     0 19778
     2       0  2652  2652
     3       0  1014  1014
     4       0   538   538
     5       0   737   737
     6       0   623   623
     Sum 19778  5564 25342
> addmargins(with(my_hc2013_data, table(cholck53,xcholck53 )))
        xcholck53
cholck53     1     2   Sum
     -9      0     0     0
     -8      0     0     0
     -7      0     0     0
     -1      0     0     0
     1   14850     0 14850
     2       0  3153  3153
     3       0  1170  1170
     4       0   696   696
     5       0   909   909
     6       0  3764  3764
     Sum 14850  9692 24542
> addmargins(with(my_hc2013_data, table(xbpchek53,xcholck53 )))
         xcholck53
xbpchek53     1     2   Sum
      1   14667  4379 19046
      2     163  5225  5388
      Sum 14830  9604 24434
> 
> # create an object with design variables and data
> design<-svydesign(id=~varpsu,strat=~varstr, weights=~perwt13f, data=my_hc2013_data, nest=TRUE)
> 
> # calculate survey Kappa
> svykappa(~xbpchek53+xcholck53, design)
Error in names(probs) <- nms : 
  'names' attribute [15] must be the same length as the vector [8]

#################################################################

Pradip K. Muhuri,  AHRQ/CFACT
 5600 Fishers Lane # 7N142A, Rockville, MD 20857
Tel: 301-427-1564




-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Muhuri, Pradip (AHRQ/CFACT)
Sent: Thursday, June 16, 2016 2:06 PM
To: David Winsemius
Cc: r-help at r-project.org
Subject: Re: [R] dplyr's arrange function - 3 solutions received - 1 New Question

Hello David,

Your revisions to the earlier code have given me desired results.

library("gtools")
mydata[ mixedorder(mydata$prevalence_c, decreasing=TRUE), c("indicator", "prevalence_c")  ]

Thanks,

Pradip


Pradip K. Muhuri,  AHRQ/CFACT
 5600 Fishers Lane # 7N142A, Rockville, MD 20857
Tel: 301-427-1564





-----Original Message-----
From: David Winsemius [mailto:dwinsemius at comcast.net] 
Sent: Thursday, June 16, 2016 12:54 PM
To: Muhuri, Pradip (AHRQ/CFACT)
Cc: r-help at r-project.org
Subject: Re: [R] dplyr's arrange function - 3 solutions received - 1 New Question


> On Jun 16, 2016, at 6:12 AM, Muhuri, Pradip (AHRQ/CFACT) <Pradip.Muhuri at ahrq.hhs.gov> wrote:
> 
> Hello,
> 
> I got 3 solutions to my earlier code.  Thanks to the contributors.  May I bring your attention to  a new question below (with respect to David's solution)?
> 
> 1) Thanks to Daniel Nordlund  for the tips - replacing leading space with a 0  in the data.
> 
> 2)  Thanks to David Winsemius for  his  solution with the gtools::mixedorder function.   I  have added an argument to his.
> 
> mydata[ mixedorder(mydata$prevalence_c, decreasing=TRUE),  ]
> 
> 3)  Thanks to Jim Lemon's for his  solution. I  have prepended a minus sign to reverse the order.
> 
> numprev<-as.numeric(sapply(strsplit(trimws(mydata$prevalence_c)," 
> "),"[",1)) mydata[order(-numprev), ]
> 
> 
> (New)Question for solution 2:
> 
> I want to keep only 2 variables  (say, indicator and prevalence_c) in the output.  Where to insert the additional code? Why does the following code fail?
> 
>> mydata[ mixedorder(mydata$prevalence_c, decreasing=TRUE), 
>> c(mydata$indicator, mydata$prevalence_c) ]
> 


Try instead just a vector of names for the second argument to "["

 mydata[ mixedorder(mydata$prevalence_c, decreasing=TRUE), 
         c("indicator", "prevalence_c") ]

> Error in `[.data.frame`(mydata, mixedorder(mydata$prevalence_c, decreasing = TRUE),  : 
>  undefined columns selected
> 
> ********************
>> str(mydata)
> Classes 'tbl_df', 'tbl' and 'data.frame':	10 obs. of  10 variables:
> $ indicator   : chr  "1. Health check-up" "2. Blood cholesterol checked " "3. Recieved flu vaccine" "4. Blood pressure checked" ...
> $ subgroup    : chr  "Both sexes, ages =35 yrs""| __truncated__ "Both sexes, ages =35 yrs""| __truncated__ "Both sexes, ages =35 yrs""| __truncated__ "Both sexes, ages =35 yrs""| __truncated__ ...
> $ n           : num  2117 2127 2124 2135 1027 ...
> $ prevalence_c: chr  "74.7 (1.20)" "90.3 (0.89)" "51.7 (1.35)" "93.2 (0.70)" ...
> $ prevalence_p: chr  "77.2 (1.19)" "84.5 (1.14)" "50.0 (1.33)" "88.7 (0.88)" ...
> $ sensitivity : chr  "87.4 (1.10)" "99.2 (0.27)" "97.0 (0.62)" "99.0 (0.27)" ...
> $ specificity : chr  "68.3 (2.80)" "58.2 (3.72)" "93.5 (0.90)" "52.7 (3.90)" ...
> $ ppv         : chr  "90.4 (0.94)" "92.8 (0.85)" "93.7 (0.87)" "94.3 (0.63)" ...
> $ npv         : chr  "61.5 (3.00)" "92.8 (2.27)" "96.9 (0.63)" "87.5 (3.27)" ...
> $ kappa       : chr  "0.536 (0.029)" "0.676 (0.032)" "0.905 (0.011)" "0.626 (0.035)" ...
> 
> Pradip K. Muhuri,  AHRQ/CFACT
> 5600 Fishers Lane # 7N142A, Rockville, MD 20857
> Tel: 301-427-1564
> 
> 
> 
> 
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Daniel 
> Nordlund
> Sent: Wednesday, June 15, 2016 6:37 PM
> To: r-help at r-project.org
> Subject: Re: [R] dplyr's arrange function
> 
> On 6/15/2016 2:08 PM, Muhuri, Pradip (AHRQ/CFACT) wrote:
>> Hello,
>> 
>> I am using the dplyr's arrange() function to sort  one of the  many data frames  on a character variable (named "prevalence").
>> 
>> Issue: I am not getting the desired output  (line 7 is the problem, which should be the very last line in the sorted data frame) because the sorted field is character, not numeric.
>> 
>> The reproducible example and the output are appended below.
>> 
>> Is there any work-around  to convert/treat  this character variable (named "prevalence" in the data frame below)  as numeric before using the arrange() function within the dplyr package?
>> 
>> Any hints will be appreciated.
>> 
>> Thanks,
>> 
>> Pradip Muhuri
>> 
>> # Reproducible Example
>> 
>> library("readr")
>> testdata <- read_csv(
>> "indicator,  prevalence
>> 1. Health check-up, 77.2 (1.19)
>> 2. Blood cholesterol checked,  84.5 (1.14) 3. Recieved flu vaccine,
>> 50.0 (1.33) 4. Blood pressure checked, 88.7 (0.88) 5. Aspirin 
>> use-problems, 11.7 (1.02) 6.Colonoscopy, 60.2 (1.41) 7. 
>> Sigmoidoscopy,
>> 6.1 (0.61) 8. Blood stool test, 14.6 (1.00) 9.Mammogram,  72.6 (1.82) 
>> 10. Pap Smear test, 73.3 (2.37)")
>> 
>> # Sort on the character variable in descending order 
>> arrange(testdata,
>> desc(prevalence))
>> 
>> # Results from Console
>> 
>>                      indicator  prevalence
>>                          (chr)       (chr)
>> 1     4. Blood pressure checked 88.7 (0.88)
>> 2  2. Blood cholesterol checked 84.5 (1.14)
>> 3            1. Health check-up 77.2 (1.19)
>> 4            10. Pap Smear test 73.3 (2.37)
>> 5                   9.Mammogram 72.6 (1.82)
>> 6                 6.Colonoscopy 60.2 (1.41)
>> 7              7. Sigmoidoscopy  6.1 (0.61)
>> 8       3. Recieved flu vaccine 50.0 (1.33)
>> 9           8. Blood stool test 14.6 (1.00)
>> 10      5. Aspirin use-problems 11.7 (1.02)
>> 
>> 
>> Pradip K. Muhuri,  AHRQ/CFACT
>> 5600 Fishers Lane # 7N142A, Rockville, MD 20857
>> Tel: 301-427-1564
>> 
>> 
>> 
> 
> The problem is that you are sorting a character variable.
> 
>> testdata$prevalence
>  [1] "77.2 (1.19)" "84.5 (1.14)" "50.0 (1.33)" "88.7 (0.88)" "11.7 (1.02)"
>  [6] "60.2 (1.41)" "6.1 (0.61)"  "14.6 (1.00)" "72.6 (1.82)" "73.3 (2.37)"
>> 
> 
> Notice that the 7th element is "6.1 (0.61)".  The first CHARACTER is a "6", so it is going to sort BEFORE the "50.0 (1.33)" (in descending order).  If you want the character value of line 7 to sort last, it would need to be "06.1 (0.61)" or " 6.1 (0.61)" (notice the leading space).
> 
> Hope this is helpful,
> 
> Dan
> 
> Daniel Nordlund
> Port Townsend, WA USA
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see 
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see 
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius
Alameda, CA, USA

______________________________________________
R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.



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