epidata教程的ppt

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)
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
Use of EpiData
(questionnaire design and entry)
Jurgita Bagdonaite
Jurmala, Latvia, 2006
Based on EPIET material
Introduction to EpiData
• • • • • Data entry and documentation Free program Based on EpiInfo Windows format No limit on No of observation (tested with >100.000)
• 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)
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)
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
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:
– (click MBaidu Nhomakorabeake data file > preview data form)
Structure of questionnaire
Three sections:
– Field name (variable) – Text describing field – Input definition (number/ letters/ date)
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>
– – – – – – Numeric Text Date Soundex Boolean (Yes/No) Autonumber
Text variables
• Information of text and/or numbers • Holding information (e.g. names, addresses) • UPPER CASE
• 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
• 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)
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
– 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
Numeric variables
• Numerical information • Hold integers (whole numbers) or numbers with a decimal point • Length (digits, decimals after the comma) • <#>, <##.#>
• 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
EpiData (II)
• Simple surveys – one questionnaire • Complicated surveys – few questionaires If there is ID – possible to merge data
EpiData files
• .QES file
– 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) • <_>
– <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……
• Soundex:
– Coding of words (anonymous, eg. A-123) – Code to limit orthographic errors (eg. Rome and Roma) – <S >
System variables
• Values generated automatically • Today date: date of the data entry
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)
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