Epidata lecture note

EpiData Applications
(questionnaire design and entry)
Getachew Hailu
(BSc in PH, MPH, Asst. Prof. In Epidemiology)
Lecturer
Public Health Department
Medical and Health Science College
Debremarkos University
Ethiopia
Tel. +251936324779
E-mail. getachewmph35@gmail.com

2
Contents
Contents of presentation:
1. Introduction to EpiData
2. Define Data/Creating Questionnaire
3. Make Data file
4. Add/Revise Checks - at Entry of Data
5. Enter Data (Data Entry)
6. Document Data
7. Export for analysis and securing data.

What is EpiData?
• A program for Data Entry & documentation of data.
• EpiData will not interfere with your computer setup
• Free public domain program
• Designed based on Epi-Info
• Has a Windows format
• No limit on No of observation (tested with >250.000)
• User friendly with other statistical packages
• The length of explaining texts for numerical or string
codes is 80 & of the codes as such is 30 characters.

Features in EpiData
Version 3.1 of EpiData includes the following features:
1. An editor where multiple questionnaire definition (.QES) files may
be created or modified including find / replace, copy to / from
clipboard, and undo functions.
2. An easy to use field alignment function
3. A test data form function allowing questionnaires to be previewed
without creating a data file
4. Creation of data files based on .QES files
5. Automatic naming of variables based on the text before the variable
6. Basic entry validation
7. Check rules
8. Beep /sounds emitted on error
9. Create new data records and view / modify existing records

Features in EpiData….
10. Export of data files to text, dBase III, Excel, Stata, SPSS &SAS
11. Import of data from text files, dBase III/IV and Stata files
12. Data file compatibility with Epi Info v6.xx
13. Work process toolbar, help structured data creation &check files
14. Create a questionnaire (.QES) file from data (.REC) file
15. Backup of data file
16. Print Data Form
17. Data file labels, variable labels and value labels
18. Revise structure of data file with revised .QES file
19. Case wise data listing & enhanced data documentation functions

Features in EpiData….
20. Indexing of data files for fast searching
21. Double-entry and validation
22. Facilities to implement hierarchical coding schemes.
23. Functions to handle different languages in menus, dialogs, etc.
24. Relational data entry
25. Merge / append data files
26. Batch consistency check of data files
27. Batch recoding of data files
28. Implementation of user defined extensions to the check file
language

EpiData Major functions
1. Creating questionnaire template
2. Controlled data entry
3. Documenting and printing data
4. Correction of questionnaires, records
5. Comparing of 2 data files/double entry verification
6. Importing and exporting data
7. Append and merge data
8. Simple analysis
 Simple surveys – one questionnaire
 Complicated surveys – few questionnaires
 If there is ID – possible to merge data

EpiData files
1. .QES file
– (EpiData Questionnaire file)
– Questionnaire
2. .REC file
– (EpiData Data file)
– Actual data
3. .CHK file
– (EpiData check file)
– Any defined checks
4. .NOT file
– (EpiData entry notes)
5. .LOG file
– (EpiData documentation file)

EpiData Window
Work Process toolbar
Editor toolbar
The EpiData screen has a “standard” windows layout
with
one menu
line/bar
Two toolbars
1. Work Process toolbar
2. Editor toolbar
One Title
line/bar

EpiData workflow
 The "Work Process toolbar "guides you from
“1. Define data" to “6. Export data” for analysis.
2. Make Data File 6. Export Data4. Enter Data
1. Define Data 5. Document3. Set up Checks

EpiData Work Process toolbar
Drop Down Menus
New. QES file
Open. QES file

Drop Down Menus
Make Data file
Preview Data Form

Drop Down Menus
File Structure
Data Entry Notes
View Data
List Data
Codebook
Validate Duplicate files
Consistency Check
Count Records

Drop Down Menus
Backup
Text
dBase III
Excel
Stata
SPSS
SAS
EpiData

2. Define Data/ Creating
Questionnaire template

Opening Existing Questionnaire
Click The drop-down menu on Define Data
Select Open .QES file

Creating New Questionnaire File
Click The drop-down menu on Define Data
Select New .QES file

Creating New questionnaire.....
New Questionnaire can be created by either of
three techniques :
 By typing in window
 By cut and paste from Word documents
 By Clicking QES file from REC file from the
tools in the menu bar

Structure of questionnaire
Any Questionnaire file in EpiData has three sections:
1. Field name (variable)
2. Text describing field
3. Input/Field/Variable definition (number/ letters/ date)

1. Field name (variable)
 Field name should fulfill the following
Criteria:
 No more than 10 characters
 Begin with a letter
 No spaces or punctuation marks

1. Field Names....
 Names of the entry fields in a data form are created
in two different ways:
1) First word in the question (i.e. the text to the left of the
field) is used as the field name.
2) Automatic field naming according to the rules used by Epi
Info.
 The method used depends upon the options defined
in File / Options / Create Data file.
 Note also that the case for variables is defined here.
 This is particularly useful when exporting to e.g. Stata,
in which fieldnames are case sensitive.

1. Field Names.....
 The method used depends upon the options
defined in File / Options / Create Data file.

1.1. First word as field name….
 If the option First word in question is field name is
selected from File / Options / Create data file,
 then the names of the entry fields are created by using
the first word in the text to the left of the entry field.
 If the length of the first word is more than 10 characters
then the first 10 characters of the first word will be used
as the field name.
 Examples: in the line
v1 Enter age of patient ###
 In a .QES file will give the 3-digit integer field the field
name "v1" if the option First word in question is field
name is selected.

1.2. Automatic field names....
 If Automatic field names is selected in the Create
data file options (File / Options / Create data file),
 EpiData automatically generates field names based on
the field's question (i.e. the text to the left of the field).
 The field name is a maximum of 10 characters starting
with a letter. Letters used in the name are A-Z.
 The field name is generated from the beginning of the
field‟s question.

 The following rules are used when generating the field names:
No Rule Example
1  Text enclosed in braces
(curly brackets)
 is used in preference to
normal text.
 Braces offer a powerful
method of defining
meaningful field names.
If the question is “{my}
first {field}”
then the field name will
be MYFIELD
2  Common words are
skipped.
 i.e. words like “what”, “the”,
“of”, “and” etc..
“What did you do?”
generates the field name
YOUDO.

 The following rules are used when generating
the field names:
No Rule Example
3 Fields without a
question get the
same name as the
previous field
plus a number
 If the previous field is named MYFIELD
 then the next field is named MYFIELD1.
 If the previous field is named V31
 then the next field is named V32
 If no previous field exists then the
default name FIELD1 is used

 The following rules are used when generating
the field names:
No Rule Example
4 If the first character of the
generated field name is a
number then the letter N is
inserted at the first character
“3 little mice”
generates the field name
N3LITTLEMI.
5 Letter case of the field name is
based on the settings used in
File / option/Create Data file
Upper case
Lower Case
Leave as it

2. Variable labels/
Text describing field
 A variable label is a description of the data that a field
contains.
 In EpiData the variable label is generated
automatically by using the text to the left of the field
in the .QES file.
 If the option First word in question is field name is set
then the variable label will be the text to the left of the
field excluding the first word, which is used as the
field name.

2. Variable labels/
Text describing field......
 Example: in the line
v1 Age of patient ###
 if the option First word in question is field name is
set, will create the field name "v1" and the variable
label "Age of patient”.
 If the option Automatic field naming is set then the
field name will be "v1ageofp" and the variable label
will be "v1 Age of patient".

3. Variable/Field types in EpiData
• Define variables using “Pick List” or “Code
writer”
• Choose type of variable:
– Numeric
– Text
– Date
– Soundex
– Boolean (Yes/No)
– Autonumber

3. Variable/Field types in EpiData
 Define variables using “Pick List” or “Code writer”
 Choose type of variable:
 Numeric
 Text
 Date
 Soundex
 Boolean (Yes/No)
 Autonumber

3.1. Text variables
 Are Variables of information of text and/or numbers
 Holding information (e.g. names, addresses)
 UPPER CASE
 Can only hold upper case (capital) letters
 Lower case variable automatically converted into upper
case text (ex: Egypt converted into EGYPT)
 No mathematical operations
 Length (How many characters)
 <_> (encrypted fields-special type of text fields)

3.1. Text variables
 Use encrypted fields to store data in a protected
mode,
 e.g. personal information.
 The number of underscore characters defines the
length of the field.
 Text fields accept all characters.
 The maximum field length is 80 characters.

3.2. Numeric variables
 Are variables of Numerical information
 Hold integers (whole numbers) or numbers with a
decimal point
 Length (digits, decimals after the comma)
 ### , ###.### , ######## , ##.####
 Numeric fields accept entry of numbers, the minus
sign and decimal points.

3.2. Numeric variables
 Periods (.) as well as commas (,) are accepted as
decimal points in both the .QES file and during
data entry.
 Only one decimal point is accepted in a field.
 This means that commas cannot be used as thousand
separators.
 The number of characters (including a decimal
point) define the length of the field.
 Maximum field length is 14 characters.

3.3. Boolean Variables
(yes/no fields)
 Are logical or YES/NO variables
 Variables with only two possible answers: Yes or No
 <Y>
 Boolean fields accept only Y, N, 1, 0 and space as legal
entries.
 An entry of "1" is converted to "Y".
 An entry of "0" is converted to "N".
 Boolean fields have a length of one.
 This means that a field code of <Y > in the .QES file will
create an error

3.4. Date variables/ fields
 Hold information on dates
 There are three types of date fields:
1. European style dates (day/month/year), (dd/mm/yyyy)
2. American style dates (month/day/year), (mm/dd/yyyy)
3. "reversed dates" (year/month/day), (yyyy/mm/dd)
 Date fields are always 10 characters in length.
 During data entry, legal characters are numbers
and forward slash (/).
 Dates can be entered without using the slash
character if all numbers are written in full.

 The date 4th of May 1999 can be entered as
04051999 if the field is of the European type
date.
 When the focus is changed to the next field, the
date field will be formatted to the standard
format (04/05/1999).
 It is not necessary to type all 10 digits.
 If the entry is 040599 in a European date field,
the field will be formatted to 04/05/1999.

 2-digit years are interpreted as the belonging to
the century 1900 for years between 50 and 99 and
the century 2000 for years between 00 and 49.
 If the entry is 0405 in a European date field, then
the current year is added to the field.
 After entry, all types of date fields will be checked
to make sure a legal date was entered.
 EpiData only supports dates with 4 digit years.

3.5. Soundex variables/fields
 Soundex fields accept all characters, but only the
letters in the last word of the entry will be used to
create the Soundex code.
 <S >
 Soundex is a coding of words that can be used to
anonymize e.g. the surnames of informants
participating in a survey.
 A Soundex code is always in the format A-999, that
is one upper-case letter, a hyphen and 3 numbers.

 The Soundex code is generated using the following
rules:
1. The first letter of the word is always retained. The
rest of the surname is compressed to a three digit
code based on the following coding scheme:
1. A E I O U Y H W Not coded
2. B F P V Coded as 1
3. C G J K Q S X Z Coded as 2
4. D T Coded as 3
5. L Coded as 4
6. M N Coded as 5
7. R Coded as 6

S.No Rule Example
1. 2 Consonants after the initial letter are coded in
the order they occur
HOLMES = H-452
ADOMOMI = A-355
1. 3 The code always uses the initial letter plus
three digits. Further consonants in long words
are ignored:
VONDERLEHR = V-536
1. 4 Zeros are used to pad out shorter names: BALL = B-400
SHAW = S-000
1. 5 Double consonants are treated as one: BALL = B-400
1. 6 As are adjacent consonants from the same
code group:
JACKSON = J-250
1. 7 A consonant immediately following an initial
letter from the same code group is ignored:
SCANLON = S-545
1. 8 Apostrophes and hyphens are ignored: KING-SMITH =
KINGSMITH = K-525
1. 9 Consonants from the same code group
separated by W or H are treated as one:
BOOTH-DAVIS = B-312

3.6. System variables/fields
 Values generated automatically
 Today date: date of the data entry
 <Today-dmy>
 <Today-mdy>
 <Today-ymd>
 Auto identification number:
 Counts the records entered.
 <IDNUM>

Editor
 The primary purpose of the EpiData editor is to
create questionnaires (.QES files).
 But also to handle output from documentation
procedures.
 The user-interface should be familiar as it uses
standard Windows functions.
 Some functions, however, are not found in other
programs:
 The Field Pick List, The Code Writer, Preview Data form
Auto Indention, Align Entry fields.

The Field Pick List
 The field pick list shows, on tabbed pages, the field
types available in EpiData.
 When the pick list is open, you can select a field type
to be inserted at the current position of the cursor in
the current editor window.
 A field type is selected by choosing the page
containing the desired field type, then setting the
properties of the field and clicking on [Insert] (or
pressing the [Enter] key).

The Field Pick List…..
 The pick-list can be opened:
1. by pressing [Ctrl] + [Q]
2. by a click on the Field Pick List button found in the
editor toolbar
3. by selecting Field Pick List in the Edit menu
4. Pressing [Ctrl] + [Q] when pick list is shown changes
focus from the editor window to the pick list window.
 Remove the pick-list by:
1. Clicking the close control on the pick list window
2. Pressing [Ctrl] + [F4] when the pick list has the focus

Code Writer
 The Code Writer is a helper function making it
easier to type the codes used to define :
 the field type and
 length in questionnaire (.QES) files.
 If Code Writer is enabled certain keystrokes will be
interpreted as the beginning of a field definition and
 Code Writer will complete the code or will ask for
information on the length of the field before writing
the code in the questionnaire (.QES) file.

Code Writer…..
 For example, if you type the character #, Code
Writer will interpret this as the beginning of a
numeric field and
 will prompt you for the length of the numeric field.
 When you have entered the length, the numeric
field will be inserted in the current editor window
in the current cursor position.

Code Writer…..
Character Field type prompted for length of field
# Numeric Type 5 to get an integer field of five digits in
length (#####).
Type 5.2 or 5,2 to get a floating point field with
five digits before and two digits after the decimal
place (#####.##).
__ Text yes
<E Encrypted yes
<A Upper-case
text field.
Yes-- Latter case of the "A" is not
important.
<d European style date <dd/mm/yyyy> will be inserted.
 The following character combinations are recognized by Code
Writer:

Code Writer…..
Character Field type prompted for length of field
<i Automatic
ID-number
Yes - Default length (and smallest
possible length) is five characters.
<s Soundex yes
<m American style date <mm/dd/yyyy> will be inserted.
<y Boolean field <Y>will be inserted
<d European style date <dd/mm/yyyy> will be inserted.
 The following character combinations are recognized by Code
Writer:

Code Writer…..
 Toggle Code Writer on and off:
 by pressing [Ctrl] + [W]
 by a click on the Code Writer button found in the
editor toolbar
 by selecting Code Writer in the Edit menu
 Pressing [Ctrl] + [Q] to open the Field Pick List will
turn off the Code Writer.
 Opening the Code Writer will turn off the Field Pick
List.

Auto indention
 When the editor in EpiData is used to create
indented text the option Auto Indent may be useful.
 If the option is selected then new lines will
automatically be indented with the same number of
blank characters as the previous line.
 This is especially useful when using the editor to
create check files.
 Command :
Put the cursor on
1st line
From the menu
bar Click on Edit
Click Auto
indent.

Aligning entry fields
 The Align Fields function can be used in the editor
when a questionnaire (.QES) file is being written.
 Command :
 The result of Align Fields is dependent on the setting
of field naming (see File / Options / Create data file).
Place the cursor in a line in
the editor which contains
an entry field that has the
desired position on the line
Select Align
Fields from
the Edit
menu.

Aligning entry fields……
 If First word is field name is the current setting then
these lines
v1 A small text ####
v2 Other text <A > v3 ###.#
v3 Text ###
 will be changed to
v2 Other text <A > v3 ###.#
v3 Text ###
 provided the cursor was placed in the v1-line before
Align Entry fields was called.

Aligning entry fields……
 If field naming is set to Automatic field naming then
the result will be:
V2 Other text <A > v3 ###.#
v3 Text ###

Preview Data Form
 The Preview Data Form function shows the layout of
the questionnaire as it is shown during data entry but
without creating a data (.REC) file.
The fields shown in Preview Data Form behave in the
same way and have the same names and lengths as
during data entry, giving a realistic impression of how
the questionnaire works.
Check functions are not applied when Preview Data
Form is used because no data file is created.

Preview Data Form.....
 It is not necessary to close a Preview Data Form
window before a new Preview Data Form can be run.
The preview of the data form is not updated
automatically when you make changes to the
questionnaire (.QES) file.
You should run Preview Data Form again to preview
the effect of changes made in the questionnaire
(.QES) file.

Preview Data Form.....
 When a questionnaire definition is show in an editor
window, Preview Data Form can be run by:
 pressing [Ctrl] + [T]
 clicking the Preview Data Form button in the editor toolbar
 choosing Preview Data Form in the Data File menu
 choosing Preview Data Form in the editor pop-up menu
 choosing Preview Data Form in the drop-down menu to the
Make Data File button on the work process toolbar.

Create data file
 Create a data (.REC) file by:
 selecting New File from the Data menu in the main screen, or
 by clicking the Make Data File button in the work process
toolbar, or
 by selecting Make Data File in the Data File menu in the
editor
 It is not necessary to open a questionnaire (.QES) file
in the editor before creating a data (.REC) file.
 If no questionnaire (.QES) file is open in the editor
then a select files dialog will be shown.

Create data file....
 The data (.REC) file will, by default, have the same
name as the questionnaire (.QES) file by default, but
with the extension .REC instead of .QES.
 Using the same name for .QES and .REC files is
recommended but is not required.
 An optional short description of the data file can be
entered (maximum of 50 characters).
 The short description is called the data file label.
 The data file label will be shown as part of the data
file's documentation and it is saved as part of the data
file created when exporting to Stata.

Create data file....
 Before a data file is created it may be previewed if the
.QES file is open in the editor by selecting Preview
Data Form from the Data File menu or by pressing
[Ctrl] + [T].
 WARNING: An existing data file will be deleted and
the data will be lost if a new data file is created with
the same name.
 To modify a data file without losing data, e.g. to add a
field or change the field type of a field, please use
Revise Data File.

Now You have gone through
 Saving questionnaire
 Creates .QES file
 Create Data file
 Click Make Data file button > Make Data file
 Creates .REC file
 Questionnaire and Data file ready
 But……there will be errors in data entry

Errors in data entry
 Tranposition (ex: 39 becomes 93)
 Copying errors (0 copy as an “o” letter)
 Consistency errors: two or more responses are
contradictory (sex: man, pregnancy=Yes)
 Range errors: answers outside of probable or
possible values (ex: heigh = 3 metres)

Preventing errors
 Standardised and previously tested questionnaire
 Training the interviewers and data entry clerck
 Checking &validating paper forms of questionnaires
 Checking during data entry (Check module Epi-Data)
 Validation: entering twice data by different operators
 Checking after data entry (Analysis module Epi-Info)

4. Add/Revise Checks
at Entry of Data

4.1. Checks Files
 Reduce errors in input
 Rather than checking the data after all data has
been entered,
 It may be useful to check the validity of the data
during the data entry process.
 Using a check file makes this possible.
 A check file describes ways of checking the
validity of the entered data for one, several, or all
of the entry fields.

4.1. Checks Files
 The check file can also contain commands to
control the flow of data entry:
 e.g. automatic jumps from one entry field to another
field based on the data entered)
 A check file must have the same name as the
data file but with the extension .CHK instead
of .REC.

4.1. Checks Files
 Examples of operations that can take place during the
data entry process if programmed in a check file:
1. Limiting entry of numbers or dates to a specific range or to
a number of specified values
2. Forcing an entry to be made in a field
3. Copying the data from the previous record to a new record
4. Making conditional jumps to other fields based on the data
in one field
5. Calculate values of fields based on the values in other fields
6. Complex calculations and conditional operations
(IF..THEN operations)
7. Help messages to the person entering data

4.1. Checks Files
 A check file is created after creating a data file.
 The check file may be created in two ways:
1) By using Add / Revise found on the Checks menu, or
by clicking the third button on the work process
toolbar.
 This method can be used to specify or change checks for
the fields,
 but blocks outside the field blocks e.g. BEFORE FILE, etc.
 can only be specified or changed using the editor.

4.1. Checks Files
2) By using the editor to manually write all check
commands.
 Remember to save the check file with the same name
as the data file, but with the extension .CHK instead
of .REC.
 It is possible to use both methods,
 using Add/Revise Checks to add basic checks and
 the editor to add more complex checks or file level
(rather than field level) checks.

4.1. Checks Files
 If a check file exists when Enter Data is selected
 Then the commands in the check file will be loaded
automatically at the same time as the selected data file.
 The most basic check commands can easily be programmed
using the Checks / Add / Revise function. This includes:
1. range checking,
2. specification of legal values,
3. making a field required,
4. making conditional jumps between fields,
5. making a field the value of the previous record,
6. using value labels.
 If you only want to use these commands then continue to
Add / Revise Checks.

4.2. Add/Revise Checks
 Once Data file is created:
 Click Checks button > choose .REC file > then

 This function adds or revises checks (validation
rules) to an existing data file.
 When a data file is selected, a data form is built
and the check functions window is shown.
 The [F6] key toggles the focus between the data
form and the check functions window.
 If the focus is in the data form then pressing [Ctrl] +
[Right Arrow] key will change the focus to the check
functions window.

 If the focus is in the check functions window then
pressing [Ctrl] + [Left Arrow] key will change the focus
to the data form.
 Select the entry field to add validation rules by:
 Selecting it in the data form (use a mouse click or [TAB]
and [Enter] to reach the field).
 Using the field name pick list at the top of the check
functions window.
 Pressing [Ctrl] + [Up Arrow] or [Ctrl] + [Down Arrow]
key when focus is in the check functions window.

 If the check functions window has the focus you
can use:
 The [Arrow] keys,
 The [TAB] key or
 The [Enter] key to reach one of the five basic checks
 This are:
1. Range/legal
2. Jumps
3. Must Enter
4. Repeat
5. Value Labels

4.2.1 Range / Legal
 If focus is in a field on the data form
 Then [Ctrl] + [L] will make the cursor jump to the
Range/Legal definition line.
 A range is defined by typing the minimum value
and the maximum value separated by a hyphen.
 Typing 2-5 defines that only the numbers 2,3,4 or 5
can be entered in the current field.

4.2.1 Range / Legal
 If only a maximum value is wanted then use -INF
(minus infinity) as the minimum value.
 Typing -INF-5 defines all numbers less than or equal to
5 as legal entries in the current field.
 If only a minimum value is wanted then use INF
(infinity) as the maximum value.
 Typing 0-INF defines all positive numbers as legal
values.

4.2.1 Range / Legal
 Legal values are defined by typing all the accepted
values separated by spaces or commas.
 Typing 4,6,8,10 defines that only the numbers 4,6,8 or 10
can be entered in the current field.
 If both a range and legal values are defined then the
range must be entered before the legal values.
 Typing 2-6, 8 defines the numbers 2,3,4,5,6 and 8 as legal
values. The definition 8, 2-6 will result in an error.
 If you want to use a comma instead of a dot as the decimal
separator please enclose the definition in double quotes.

4.2.2 Jumps
 Jumps define which entry field receives the focus
for particular values entered into the current
field.
 If, for example, the current field contains a sex
(1 = male, 2 = female),
 Then the jumps can define that the value of 1 gives the
focus to the field V23 and the value of 2 gives focus to
another field, e.g. V40.
 Type [Ctrl] + [J] to move the focus from a field in
the data form to the jumps definition line.

4.2.2 Jumps
 Jumps are entered by specifying the value,
entering a greater-than-sign (>) and specifying
the name of the field to jump to.
 For example, 1>V23, 2>V40 defines that
 an entered value of 1 makes the entry continue in the
field named V23 and
 an entered value of 2 makes the entry continue in the
field named V40.
 Note that Jumps are separated by commas.

4.2.2 Jumps
 If spaces or commas are used in a definition,
enclose the whole definition in double quotes
(e.g. “2.5>V30”, “3,5>V35”).
 Instead of specifying a field name as the target
for a Jump, two special targets may also be used:
 END and WRITE.
 END means “jump to the last field in the data form”,
 WRITE means write the current record to the disk.

4.2.2 Jumps
 For example, the Jumps definition
 “1>V30”,”2>END”,”3>WRITE” specifies the following
behaviour:
 If the number 1 is entered then data entry continues
in the field named V30;
 if the number 2 is entered then data entry continues
in the last field in the data form;
 if the number 3 is entered then the current record is
saved.

4.2.2 Jumps
 A general jump command can be entered as
“AUTOJUMP V30”.
 This means that the next field that receives the focus
will be the field named V30 regardless of the data
entered in the field containing this jump condition.
 If AUTOJUMP is used this must be the only entry in
the jumps edit box.
 AUTOJUMP is useful for entering data from forms
which do not follow the normal left-to-right, top-to-
bottom completion order (e.g. forms arranged in
columns).

4.2.2 Jumps
 To make definition of jumps faster, the following
short-cut can be used:
 When the value of a jump and the following ">" has
been written, click with the mouse on the field that
the jump should go to.
 The name of the clicked field will be inserted after
the ">".
 The same point-and-click can be used after writing
AUTOJUMP (remember to type a space before
attempting to click on the destination field).

4.2.3 Must Enter
 This rule defines if data must be entered into
the current field.
 Pressing [Ctrl] + [E] when a field in the data form
has the focus during Add / Revise Checks will
toggle the field‟s Must Enter status

4.2.4 Repeat
 If Yes is entered in this rule then the data
entered in the previous record will be repeated
in the next new record.
 Repeated data can be changed during data entry.
 This function can save a lot of typing if your forms
contain data that changes only rarely in a particular
batch of forms (e.g. reporting forms in a surveillance
system).
 Pressing [Ctrl] + [R] when a field in the data form
has the focus will toggle the field‟s Repeat status.

4.2.5 Value labels
 In a Value Label
 Add text to explain values
 Click + to add label
 Format as shown
 Press F9 during data entry
to see labels

4.2.5 Value labels
 Value labels are a set of values combined with text items
that explain the meaning of each value.
 For example: A field is created to enter information on the
sex of the informant.
 a value of 1 in the field means that the informant is male
and that a value of 2 means the informant is female.
 The value labels in this example would be:
1 Male
2 Female
 If a value label is defined then a „translation table‟ can be
shown during data entry if the user presses [F9]
(or the [+] key on the numeric keypad).

4.2.5 Value labels
 To define a new label
 Click the button to the right of the value label drop-down
list marked with „+‟.
 This opens a small edit window with this text:
LABEL Label_field
END
 The text Label_field is based on the name of the field. You
can change this if you want to.
 The text to be entered for the example above is:
LABEL Label_Sex
1 ”Male gender”
2 Female
END

4.2.5 Value labels
 The spaces before the values are optional, but they
make the list easier to read.
 Notice the need for quotes when spaces are
included,
 e.g. 1 ”Buena Vista Social Club” or 3 ”Mongolian Horse”
 Click Accept and Close or press [Alt] + [A] to close
the edit window.
 The name of the new label will now be shown in the
Value Label drop-down list.

4.2.5 Value labels
 To edit an existing label
 Make sure that the name of the label to be edited is shown
in the Value Label drop-down list.
 Click the [+] button.
 The edit window is now shown with all labels defined for
the selected Value Label.
 Edit the labels and click Accept and Close to exit
 Press the [Esc] key (or click Cancel) to abandon the
changes.

4.2.5 Value labels
 To Assign an existing label to a field
 Click on the down arrow in the Value Label drop-
down list and select the relevant label.
 Several fields can share the same value label, which
only needs to be defined once.
 To Clear the value label for the field
 Click on the down-arrow in the Value Label drop-
down list and
 select [none].

4.2.5 Value labels
 To use predefined labels
 With the installation of EpiData a value label library
was saved in the EpiData program directory.
 The library has the filename EpiData.Lbl.
 The library is meant to be a help when the same value
labels are used often in different projects.
 When the down-arrow in the Value Label drop-down
list is clicked, the names of value label sets contained in
the library file are shown in normal font.
 Bold names signify value label sets that are part of the
check file being edited.

4.2.6 CALCULATE AGE
 One wishes to calculate the AGE as the difference between a
given data, e.g. June 6th 2001 and date of birth which was
entered in the field DOB. How to do that ? Just specify this
formulae:
 let age = round (int(("01/06/1001"-DOB)/365.25)) , This
means:
1. Take the difference in days btw. june 1st and DOB:
"01/06/2001" - DOB
2. Convert that difference into an integer:
int( "01/06/2001" - DOB )
3. Convert the result to number of years:
round( int( "01/06/2001" - DOB ) /365.25)
 round is needed since epidata cannot store a real into an
integer and AGE was a ”### field”

5.1. Data Entry
 Click Enter data button
 > choose .REC file
 For entry of Dates such as :
 15/5/2006 – type 150506 or 15/5/06
 For Value Labels:
 Press F9 to view

5.2.Navigation between records
 Navigation buttons are shown in the bottom of the data form
window. All the functions of these buttons are displayed on
the Goto menu.
 The buttons are:
Goto the first record Goto the previous record
([Ctrl] + [PgUp] or [F7]
may be used instead)
Goto the next record
([Ctrl] + [PgDn] or [F8]
may be used instead)
Goto the last record
Enter new record ([Ctrl] +
[N] may be used instead)
Delete a record or
undelete a deleted record
([Shift] + [Delete] may be
used instead

5.3. Append / Merge Data files
 Is used to combine two data files into a third
(new) data file.
 Append is used for combining two data files with
exactly or nearly the same structure.
 Files are joined end-to-end.
 Merge is used for combining two data files with
different structure that share 1-3 common fields ("ID-
fields" or key-fields).
 Files are joined side-to-side.

5.3.1 Append Data files
 Select the function Append / Merge from the
Data menu.
 Enter the name of the two data files that are to be appended.
 Click OK.
 A summary of the two selected data files is
shown.
 Enter the name of the new data file that will
contain the result of the append operation.
 The two selected data files will not be changed
during the operation.

 Append can be performed in two different ways:
1. The result data file will have the same structure (same
fields) as Data file A.
 Only data in Data file B contained in fields that exist in
Data file A will be appended.
 Data in fields that do not exist in Data file A will be
ignored.
2. The result data file will have a structure that is a
combination of all the fields of Data file A and all the
fields of Data file B.

 NOTE: Data file A is considered the „master‟ data file.
 If a field exists with the same name in Data file A
and Data file B then the same field in the result
data file will have the same field type as the field
in Data file A.
 NOTE: If either Data file A or Data file B has a check
file Append/Merge will combine the check files into
one check file for the combined file.

 It is up to the user to control and confirm proper
action of the various check commands in the
combined file.
 Pay particular attention to labels jumps, goto
statements and if ... then .... endif structures.
 After running append a summary of the result
data file is shown.
 The summary is also added to the data entry notes file
of the result data file.

5.3.2 Merge Data files
 Merge requires one or more key fields to be
present in both files in order to make it possible
to match a record from Data file A to a record in
Data file B.
 Up to three key fields can be selected.
 The key fields do not have to be marked as KEY
or KEY UNIQUE fields in the check file, but they
must exist in both data files.

 When the Merge page is selected, a list of
common fields from Data file A and Data file B is
shown.
 If no common fields exist, then merge cannot be run.
 Select from 1 to 3 fields in the list of common fields.
 The combined key fields must be unique in both data
files.

 Two types of merge can be done:
1. Merge only records where the key (combined key
fields) matches in both Data file A and Data file B.
2. Merge all records of both data files.
 This option may result in many fields with missing
values since some records from Data file B may have no
matching record in Data file A.
 In order to do a merge one or more common fields
must exist

Document Tools
 File Structure
 Data entry notes ( .NOT file)
 Use to write comments during data entry eg: difficult to read
handwriting etc
 View Data
 List Data
 Codebook
 Basic descriptive statistics on all variables
 Validate duplicate files
 Check consistency after double entry

Export to other programs
 Click Export data button
 Choose program
 The Export data function is found in the Data in/out menu
and includes:
1. backup of data
2. text file format
3. dBase III format
4. Excel format
5. SPSS format
6. Stata format
7. SAS format
8. new EpiData data file
 For Epi-info open .REC file directly

References
1. EpiData Help file: Version 3.1: Data entry and data documentation
http://www.epidata.dk
2. ©Jens M. Lauritsen & Michael Bruus. The EpiData Association,
Odense Denmark Version of : November 26th 2004.
3. Lauritsen JM & Bruus M. EpiData (version 3.1). A comprehensivetool for
validated entry and documentationof data. The EpiData Association, Odense
Denmark, 2004.
4. Lauritsen JM, Bruus M. EpiTour - An introduction to validated
dataentry and documentation of data by use of EpiData. The EpiData
Association, Odense Denmark, 2005.

Epidata lecture note

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Epidata lecture note