Data Collection and Management for Clinical Research

Michael A. Kohn, MD, MPP31 August 2010

Topics

Data Tables: rows = records, columns = fields

Data Dictionary: a table of data about your data table(s)

On-screen data collection forms

Data Tables

Study data are stored in one or more data tables in which –

Rows = Records = EntitiesColumns = Fields =

Attributes

Interview Data

Exam Data

Questionnaire Data

Outcomes on same form as predictors

Demonstration: Creating a Data Table

Label columns and enter rows of data in datasheet view

Demonstration: Data Dictionary

Table design view:•field (=column) names, •data types, •definitions, •validation rules

Demonstration: Data Validation

Disallowed values

Duplicate primary keys

(SubjectDemo)

(Subject)

Demonstration: Same Table in Excel, Stata

Excel Stata Etc

Rows = Records = EntitiesColumns = Fields =

AttributesAccess and Stata have a special row at the top for column headings (=field names); Excel just uses the first row.

Data Collection Forms

Nothing focuses the study like the need to develop a data collection form

Forces you to get concrete about your predictors, outcomes, and other measurements.

Planning Data Collection and ManagementSearch the internet and ask other researchers for

already developed data collection forms.Draft your data collection form.Test your data collection form with dummy subjects

and, even better, with real (de-identified) study subjects.

Enter your test data into a data table with rows corresponding to subjects and columns corresponding to data elements. (Use Excel, Access, Stata, or even Word.)

Create a data dictionary.Decide who will collect the data, and when/how the

data will be collected.

NHAMCS

nhamcs100-ED_2007.pdf

From Paper Data Forms to Data Table(s)*

Transcription directly into the table(s) Transcription via an online (screen) form Scanning using OMR software

*Best option: Don’t use paper data collection forms at all

Creating On-Screen Forms

Microsoft Access Filemaker Pro REDCap QuesGen (today) SurveyMonkey Others

On-Screen Data Collection Forms

Demonstrate the QuesGen web form This is easy to do in SurveyMonkey

and REDCap too Access and FilmakerPro can both

create nice on-screen forms, but not as easy to make available and secure via the Internet

Clinical research studies consistently under-plan and under-budget for data management.

One FTE research assistant, including benefits, will cost your study ~$100k/year; you should be willing to spend one tenth as much for consulting on your database system.

Don’t leave data checking, validation, and cleaning for the biostatistician a) it will be too late; b) biostatisticians do not view data cleaning as part of their job.

Assignment?

Write a one-page data management section for your research study protocol.

Draft your data collection forms!