NACCulator

Converts a CSV data file exported from REDCap into the NACC's UDS3 fixed-width format.

Files

This is not exhaustive, but here is an explanation of some important files.

• nacc/: top-level Python package for all things NACC.

• nacc/redcap2nacc.py: converts a CSV data file exported from REDCap into NACC's UDS3 fixed-width format.

• nacc/uds3/blanks.py: specialized library for "Blanking Rules".

• nacc/uds3/ivp/forms.py: UDS3 IVP forms represented as Python classes.

• tools/generator.py: generates Python objects based on NACC Data Element Dictionaries in CSV.

HOW TO Convert from REDCap to NACC

Once the project data is exported from REDCap to the CSV file data.csv, run:

$ pip install nacculator
$ redcap2nacc < data.csv > data.txt

Or, if you're using the source code:

$ PYTHONPATH=. ./nacc/redcap2nacc.py < data.csv > data.txt

The program accepts two arguments -file and -(ivp|fvp|np). Both the arguments are optional. See the python help as:

  $ PYTHONPATH=. ./nacc/redcap2nacc.py -h
  usage: redcap2nacc.py [-h]
                    [-fvp | -ivp | -np | -f {cleanPtid,updateField,replaceDrugId,fillDefault,fixC1S}]
                    [-file FILE] [-meta FILTER_META]

  Process redcap form output to nacculator.

  optional arguments:
  -h, --help            show this help message and exit
  -fvp                  Set this flag to process as fvp data
  -ivp                  Set this flag to process as ivp data
  -np                   Set this flag to process as np data
  -f or --filter        Accepts one of {cleanPtid,updateField,replaceDrugId,fillDefault,fixC1S}
                        Set this flag to process the filter
  -file FILE            Path of the csv file to be processed.
  -meta FILTER_META     Input file for the filter metadata (in case cleanPtid is used)

Example Usage

PYTHONPATH=. ./nacc/redcap2nacc.py  -np -file data.csv > data.txt

To use a filter,

PYTHONPATH=. ./nacc/redcap2nacc.py  -f cleanPtid -meta someFileName.csv < data.csv > data.txt

Only cleanPtid filter requires a meta file to be passed to it. Other filters do not need a meta tag.

Note: output is written to STDOUT; errors are written to STDERR; input can be STDIN or the first argument passed to redcap2nacc.

If there are no errors, then submit the data.txt file to NACC.

HOW TO Use nacculator to filter data

If your data is not clean enough to be processed by nacculator, there are some built in functions to clean (read transform) the data.

• cleanPtid

  This filter requires the meta option to be set using the -meta flag. The meta file can be a csv file of ptids to be removed. All the records whose ptid is found in the passed meta file will be discarded in the output file.

  Example meta file:

  $ cat sampleRemovePtidFile.csv
  ptids
  110001
  110003
  

• replaceDrugId

  This filter replaces the first character of non empty fields of columns drugid_1 to drugid_30 with character "d"

  This filter does not require any meta data file as of now.

• fixC1S

  This filter fixes the column names of some of the fields in C1S form. This filter does not check for any data. It always replaces the column names if found.

  Currently, below replacements are used:

  c1s_2a_npsylan    ->  c1s_2_npsycloc
  c1s_2a_npsylanx   ->  c1s_2a_npsylan
  b6s_2a1_npsylanx  ->  c1s_2a1_npsylanx
  

• fillDefault

  This filter is used to set some predefined fields to their corresponding predefined values. Below are the current defaults :

  nogds    -> 0
  arthupex -> 0
  arthloex -> 0
  arthspin -> 0
  arthunk  -> 0
  

  If field is blank, always it will be updated to default value.

• updateField

  This filter is used to update non blank fields. Currently, only adcid is updated to 41.

HOW TO Generate New Forms

Note: executing generator.py from within tools is an important step as the script assumes any corrected DEDs are stored under a folder in the current working directory called corrected.

Warning: read the warnings in the current ./nacc/uds3/ivp/forms.py first.

$ cd tools
$ PYTHONPATH=.. ./generator.py uds3/ded/csv/ > ../nacc/uds3/ivp/forms.py
$ edit ../nacc/uds3/ivp/forms

• Resources for uds3 fvp forms are available here.

FAQ

• This is developed and tested on Python 2.7
• If there are key not found errors, then your dictionary may have the value with a different name. Make sure you the name of the keys is consistent while writing and reading.