Creating horizontal dataframe from vertical table (with repeated variables) - r

Question

Need to create usable dataframe using R or Excel
Variable1
ID
Variable2
Name of A person 1
002157
NULL
Drugs used
NULL
3.0
Days in hospital
NULL
2
Name of a surgeon
NULL
JOHN T.
Name of A person 2
002158
NULL
Drugs used
NULL
4.0
Days in hospital
NULL
5
Name of a surgeon
NULL
ADAM S.
I have a table exported from 1C (accounting software). It contains more than 20 thousand observations. A task is to analyze: How many drugs were used and how many days the patient stayed in the hospital.
For that reason, I need to transform the one dataframe into a second dataframe, which will be suitable for doing analysis (from horizontal to vertical). Basically, I have to create a dataframe consisting of 4 columns: ID, drugs used, Hospital stay, and Name of a surgeon. I am guessing that it requires two functions:
for ID it must read the first dataframe and extract filled rows
for Name of a surgeon, Drugs used and Days in hospital the function have to check that the row corresponds to one of that variables and extracts date from the third column, adding it to the second dataframe.
Shortly, I have no idea how to do that. Could you guys help me to write functions for R or tips for excel?

Answer 1

for R, I guess you want something like this:
load the table, make sure to substitute the "," with the separator that is used in your file (could be ";" or "\t" for tab etc.).
df = read.table("path/to/file", sep=",")
create subset tables that contain only one row for the patient
id = subset(df, !is.null(ID))
drugs = subset(df, Variable1 %in% "Drugs used")
days = subset(df, Variable1 %in% "Days in hospital")
#...etc...
make a new data frame that contains these information
new_df = data.frame(
id = id$ID,
drugs = drugs$Variable2,
days = days$Variable2,
#...etc...no comma after the last!
)
EDIT:
Note that this approach only works if your table is basically perfect! Otherwise there might be shifts in the data.
#=====================================================
EDIT 2:
If you have an imperfect table, you might wanna do something like this:
Step 1.5) , change all NA-values (which in you table is labeled as NULL, but I assume R will change that to NA) to the patient ID. Note that the is.na() function in the code below is specifically for that, and will not work with NULL or "NULL" or other stuff:
for(i in seq_along(df$ID)){
if(is.na(df$ID[i])) df$ID[i] <- df$ID[i-1]
}
Then go again to step 2) above (you dont need the id subset though) and then you have to change each data frame a little. As an example for the drugs and days data frames:
drugs = drugs[, -1] #removes the first column
colnames(drugs) = c("ID","drugs") #renames the columns
days = days[, -1]
colnames(days) = c("ID", "days")
Then instead of doing step 3 as above, use merge and choose the ID column to be the merging column.
new_df = merge(drugs, days, by="ID")
Repeat this for other subsetted data frames:
new_df = merge(new_df, surgeon, by="ID")
# etc...
That is much more robust and even if some patients have a line that others dont have (e.g. days), their respective column in this new data frame will just contain an NA for this patient.