epidata教程的ppt

Automatic field names, examples
Question:
Did you {eat ice cream} What is your name? 2. Age
Field name:
EATICECREAM ISYOURNAME N2AGE
Variable type
• Define variables using “Pick List” or “Code writer” • Choose type of variable:
Field name (variable)
• No more than 10 characters • Begin with a letter • No spaces or punctuation marks
Field Name (II)
• First word
– Uses first word of line
– (click Make data file > preview data form)
Structure of questionnaire
Three sections:
– Field name (variable) – Text describing field – Input definition (number/ letters/ date)
– <Today-dmy> – <Today-mdy>
• Auto identification number: Counts the records entered
– <IDNUM>
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……
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)
• Automatic
– EpiData generates field names based on question – Uses first 10 letters
Childquest Child questionnaire <Y>
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
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
Data Entry (II)
EpiData (II)
• Simple surveys – one questionnaire • Complicated surveys – few questionaires If there is ID – possible to merge data
EpiData files
• .QES file
– – – – – – Numeric Text Date Soundex Boolean (Yes/No) Autonumber
Text variables
• Information of text and/or numbers • Holding information (e.g. names, addresses) • UPPER CASE
• Record navigation:
• Delete records:
– Click cross to delete – Record marked for deletion, but can be recovered
Document Tools
• File Structure • Data entry notes ( .NOT file)
– Use to write comments during data entry eg: difficult to read handwriting etc
• 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 and validating paper forms of the questionnaires • Checking during the data entry (Check module EpiData) • Validation: entering twice data by different operators • Checking after data entry (Analysis module Epi-Info)
• Soundex:
– Coding of words (anonymous, eg. A-123) – Code to limit orthographic errors (eg. Rome and Roma) – <S >
System variables
• Values generated automati the data entry
– 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) • <_>
Creating Questionnaire
• Define Data • Can either open .QES file or create one
New questionnaire
• Type in window • Cut and paste from Word documents • Preview questionnaire
Numeric variables
• Numerical information • Hold integers (whole numbers) or numbers with a decimal point • Length (digits, decimals after the comma) • <#>, <##.#>
– Questionnaire
• .REC file
– Actual data
• .CHK file
– Any defined checks
• Other notes or log files
EpiData workflow
1.Define Data 2.Make Data File 3. Set up Checks 4.Enter Data 5.Document 6.Export Data
Checks (II)
• Once Data file is created: • Click Checks button > choose .REC file
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
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 entry to see labels