Use of EpiData (questionnaire design and entry)

1. Use of EpiData(questionnaire design and entry) Jurgita Bagdonaite Jurmala, Latvia, 2006 Based on EPIET material

2. Introduction to EpiData • Data entry and documentation • Free program • Based on EpiInfo • Windows format • No limit on No of observation (tested with >100.000)

3. EpiData (I) • Creating questionnaire • Controlled data entry • Documenting and printing data • Correction of questionnaires, records • Comparing of 2 data files • Importing and exporting data • Simple analysis

4. EpiData (II) • Simple surveys – one questionnaire • Complicated surveys – few questionaires If there is ID – possible to merge data

5. EpiData files • .QES file • Questionnaire • .REC file • Actual data • .CHK file • Any defined checks • Other notes or log files

6. 1. Define Data 2. Make Data File 3. Set up Checks 4. Enter Data 5. Document 6. Export Data EpiData workflow

7. Creating Questionnaire • Define Data • Can either open .QES file or create one

8. New questionnaire • Type in window • Cut and paste from Word documents • Preview questionnaire • (click Make data file > preview data form)

9. Structure of questionnaire Three sections: • Field name (variable) • Text describing field • Input definition (number/ letters/ date)

10. Field name (variable) • No more than 10 characters • Begin with a letter • No spaces or punctuation marks

11. Field Name (II) • First word • Uses first word of line • Automatic • EpiData generates field names based on question • Uses first 10 letters Childquest Child questionnaire <Y>

12. Automatic field names • Text in curly brackets { } used in preference • Common words skipped (what, the, and, etc.) • If question starts with number, “N” is inserted before the number

13. Automatic field names, examples Question: Field name: Did you {eat ice cream} EATICECREAM What is your name? ISYOURNAME 2. Age N2AGE

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

15. Text variables • 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) • <_>

16. Numeric variables • Numerical information • Hold integers (whole numbers) or numbers with a decimal point • Length (digits, decimals after the comma) • <#>, <##.#>

17. Other variables • Boolean variables (s. logical variables s. YES/NO variables) • only two possible answers: Yes or No • <Y> • Date variables: • Hold information on dates • Data in american <MM/DD/YYYY> • European <DD/MM/YYYY> • Soundex: • Coding of words (anonymous, eg. A-123) • Code to limit orthographic errors (eg. Rome and Roma) • <S >

18. System variables • Values generated automatically • Today date: date of the data entry • <Today-dmy> • <Today-mdy> • Auto identification number: Counts the records entered • <IDNUM>

19. Save Questionnaire • Preview data • Save questionnaire • Creates .QES file • Create Data file • Click Make Data file button > Make Data file • Creates .REC file • Questionnaire and Data file ready • But……

20. 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)

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

22. Checks (I) • Reduce errors in input • Checks help with data entry • Many different types • Examples: • Limit entry of numbers to specific range • Forcing entry to be made in field • Conditional jumps • Copying the data from the previous record • Help messages • Conditional operations (ex if….then operations)

23. Checks (II) • Once Data file is created: • Click Checks button > choose .REC file

24. Checks (III) • Range, legal: • 1-3, 9 • First range then individual numbers • Tallinn, Riga, Vilnius • Fixing only min or max value • -INF-5 (all numbers inferior or equal 5) • 0-INF (all positive numbers superior or equal to 0) • Jumps: • Field: AGEYEARS • 0>AGEMONTHS • 0>AGEMONTHS, 1>ADDRESS • 1>END • MustEnter: • Data must be entered in Field

25. Checks (IV) • Repeat: • Show data from previous record • Value Label • Add text to explain values • Click + to add label • Format as shown • Press F9 during data entryto see labels

26. Data Entry (I) • Click Enter data button > choose .REC file • Dates: • 15/5/2006 – type 150506 or 15/5/06 • Value Labels: • Press F9 to view

27. Data Entry (II) • Record navigation: • Delete records: • Click cross to delete • Record marked for deletion, but can be recovered

28. 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

29. Export to other programs • Click Export data button • Choose program • Including Excel, Stata, SPSS • For Epi-info open .REC file directly

30. References • Lauritsen JM & Bruus M. EpiData (version 3.1). A comprehensive tool for validated entry and documentation of data. The EpiData Association, Odense Denmark, 2004. • Lauritsen JM, Bruus M. EpiTour - An introduction to validated dataentry and documentation of data by use of EpiData. The EpiData Association, Odense Denmark, 2005.

31. www.epidata.dk