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CohortExplorer-0.03
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/ CohortExplorer

NAME

CohortExplorer - Explore clinical cohorts and search for entities of interest

SYNOPSIS

CohortExplorer [OPTIONS] COMMAND [COMMAND-OPTIONS]

DESCRIPTION

CohortExplorer allows a detailed exploration of entities and variables from the clinical data stored under the Entity-Attribute-Value (EAV) schema also known as the generic schema. Most of the available electronic data capture and management software (e.g., i2b2, LabKey, OpenClinica, Opal, REDCap) use EAV schema as it allows the organisation of heterogeneous data with relatively simple schema. Because CohortExplorer has a generic framework it is possible to plug-in any clinical data repository following the EAV schema using the datasource API. CohortExplorer has been tested with Opal (OBiBa) and REDCap.

The application makes use of the following concepts to explore clinical repositories within the EAV framework:

Datasource

A study or a cohort.

Standard datasource

Datasource which involves observing entities (e.g., the participant or drug) at a single time-point alone.

Longitudinal datasource

Datasource which involves a repeated observation of entities over different time-points or visits.

Tables

Questionnaires, surveys or forms in a datasource.

Variables and values

The questions, which form part of the study, are called variables and values are answers to the questions. In CohortExplorer a variable is referenced as Table.Variable where table is the questionnaire that records the variable.

Static table

Questionnaires in a datasource, which record the entity data only once, are grouped under the static table. All tables within standard (or non-longitudinal) datasources are static. However, the longitudinal datasources may also contain some questionnaires that can be grouped under the static table (e.g., Demographics or FamilyHistory).

Dynamic table

Questionnaires in a datasource, which are used frequently to collate the entity data, are classed under the dynamic table. This table applies only to the longitudinal datasources.

MOTIVATION

I have not found any query tools that can standardise the EAV schema. All available clinical data capture and management software have their own EAV schema. This poses a problem when two or more research groups collaborate on a project and the collaboration involves data exchange in the form of database dump (anonymised). The research groups may have used a different EAV to store their clinical data. CohortExplorer is an attempt to standardise the entity attribute value model so any clinical respository can be plugged into it thus, enabling the users to browse the datasources using a standard command line search interface.

In addition, our group's specific query requirements also motivated me to write CohortExplorer.

FEATURES

  1. Allows the user to query datasources stored in multiple database instances.

  2. Access to datasource is granted only after authentication.

  3. Commands can be run on command line as well as interactively (i.e. console). It is easy to set-up a reporting system by adding commands to cron (under Linux).

  4. Command-line completion for options and arguments wherever applicable.

  5. Entities can be searched with/without imposing conditions on the variables.

  6. Allows the user to save commands and use them to build new ones.

  7. Datasource description including entity count can be obtained.

  8. Allows the user to view summary statistics and export the data on tables in csv format which can be readily parsed in statistical software like R for further analysis.

  9. Allows the user to query for variables and view their corresponding dictionary (i.e. meta data).

OPTIONS

-d DATASOURCE, --datasource=DATASOURCE

Provide datasource

-u USERNAME, --username=USERNAME

Provide username

-p PASSWORD, --password=PASSWORD

Provide password

-h, --help

Show usage message and exit

-v, --verbose

Show with verbosity

Note that the username and password is the same as the parent clinical repository. The command is an argument to CohortExplorer.

COMMANDS

describe

This command outputs the datasource description in a tabular format where the first column is the table name followed by the table attributes (e.g., variable_count, label etc.). The command also displays entity (count) for the specified datasource. For more on this command see CohortExplorer::Command::Describe.

find

This command enables the user to find variables by supplying keywords. The command outputs the dictionary of variables that are found. The dictionary can include, variable name, table name, unit, categories (if any) and the associated label. For more on this command see CohortExplorer::Command::Find.

This command enables the user to search for entities by supplying the variables of interest. The user has the liberty to impose conditions on the variables. For more on this command see CohortExplorer::Command::Query::Search.

compare

This command enables the user to compare entities across visits by supplying the variables of interest. The command is only available to the longitudinal datasources. For more on this command see CohortExplorer::Command::Query::Compare.

history

This command enables the user to see the history of saved commands. The user can utilise the existing information (like options and arguments) to build new commands without writing the commands again. For more on this command see CohortExplorer::Command::History.

EXAMPLES

[somebody@somewhere]$ CohortExplorer --datasource Clinical --username administrator --password describe (run describe command)

[somebody@somewhere]$ CohortExplorer -v -d Clinical -u administrator -p console (start console in verbose mode)
  
[somebody@somewhere]$ CohortExplorer -d Clinical -u guest -p find -fi cancer diabetes (run find command with aliases)

SECURITY

When setting CohortExplorer for group use it is recommended to install the application using its debian package which is part of the release. The package greatly simplifies the installation and implements the security mechanism. The security measures include:

  • forcing the taint mode and,

  • disabling the access to configuration files and log file to users other than the administrator or root (user).

BUGS

Currently the application does not support the querying of datasources with multiple arms. The application is only tested with clinical repositories using MySQL. The application is yet to be tested with repositories set-up using Oracle and SQL-server. Please report any bugs or feature requests to adixit@cpan.org.

DEPENDENCIES

CLI::Framework

Config::General

DBI

Exception::Class::TryCatch

File::Find

Log::Log4perl

SQL::Abstract::More

Term::ReadKey

Text::ASCIITable

Tie::IxHash

SEE ALSO

CohortExplorer

CohortExplorer::Datasource

CohortExplorer::Command::Describe

CohortExplorer::Command::Find

CohortExplorer::Command::History

CohortExplorer::Command::Query::Search

CohortExplorer::Command::Query::Compare

ACKNOWLEDGEMENTS

Many thanks to the authors of all the dependencies used in writing CohortExplorer and also everyone for their suggestions and feedback.

LICENSE AND COPYRIGHT

Copyright (c) 2013-2014 Abhishek Dixit (adixit@cpan.org). All rights reserved.

This program is free software: you can redistribute it and/or modify it under the terms of either:

  • the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version, or

  • the "Artistic Licence".

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details (http://www.gnu.org/licenses/).

On Debian systems, the complete text of the GNU General Public License can be found in '/usr/share/common-licenses/GPL-3'.

See http://dev.perl.org/licenses/ for more information.

AUTHOR

Abhishek Dixit